diff --git a/Ink Canvas/AssemblyInfo.cs b/Ink Canvas/AssemblyInfo.cs
index 4b68d9bc..620de358 100644
--- a/Ink Canvas/AssemblyInfo.cs	
+++ b/Ink Canvas/AssemblyInfo.cs	
@@ -49,5 +49,5 @@ using System.Windows;
 // You can specify all the values or you can default the Build and Revision Numbers
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("1.7.1.10")]
-[assembly: AssemblyFileVersion("1.7.1.10")]
+[assembly: AssemblyVersion("1.7.1.12")]
+[assembly: AssemblyFileVersion("1.7.1.12")]
diff --git a/Ink Canvas/Helpers/AutoUpdateHelper.cs b/Ink Canvas/Helpers/AutoUpdateHelper.cs
index 896c42f5..5ed1aec1 100644
--- a/Ink Canvas/Helpers/AutoUpdateHelper.cs	
+++ b/Ink Canvas/Helpers/AutoUpdateHelper.cs	
@@ -10,7 +10,9 @@ using System.Linq;
 using System.Windows.Controls;
 using System.Text;
 using System.Collections.Generic;
+using System.Threading;
 using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
 
 namespace Ink_Canvas.Helpers
 {
@@ -31,7 +33,7 @@ namespace Ink_Canvas.Helpers
         }
 
         // 通道-线路组映射
-        private static readonly Dictionary<UpdateChannel, List<UpdateLineGroup>> ChannelLineGroups = new Dictionary<UpdateChannel, List<UpdateLineGroup>>
+        public static readonly Dictionary<UpdateChannel, List<UpdateLineGroup>> ChannelLineGroups = new Dictionary<UpdateChannel, List<UpdateLineGroup>>
         {
             { UpdateChannel.Release, new List<UpdateLineGroup>
                 {
@@ -85,6 +87,15 @@ namespace Ink_Canvas.Helpers
             }
         };
 
+        // 区块任务结构体（移到类体内）
+        private class BlockTask
+        {
+            public int Index;
+            public long Start;
+            public long End;
+            public int RetryCount;
+        }
+
         // 检测URL延迟
         private static async Task<long> GetUrlDelay(string url)
         {
@@ -342,44 +353,88 @@ namespace Ink_Canvas.Helpers
             }
         }
 
+        // 通过GitHub API获取最新Release信息
+        private static async Task<(string version, string downloadUrl, string releaseNotes)> GetLatestGithubRelease(UpdateChannel channel)
+        {
+            try
+            {
+                string apiUrl = channel == UpdateChannel.Beta
+                    ? "https://api.github.com/repos/InkCanvasForClass/community-beta/releases/latest"
+                    : "https://api.github.com/repos/InkCanvasForClass/community/releases/latest";
+                using (var client = new HttpClient())
+                {
+                    client.DefaultRequestHeaders.Add("User-Agent", "ICC-CE Auto Updater");
+                    var response = await client.GetStringAsync(apiUrl);
+                    var json = JObject.Parse(response);
+                    string version = json["tag_name"]?.ToString();
+                    string releaseNotes = json["body"]?.ToString();
+                    string downloadUrl = json["assets"]?.First?["browser_download_url"]?.ToString();
+                    if (!string.IsNullOrEmpty(version) && !string.IsNullOrEmpty(downloadUrl))
+                        return (version, downloadUrl, releaseNotes);
+                }
+            }
+            catch (Exception ex)
+            {
+                LogHelper.WriteLogToFile($"AutoUpdate | GitHub Releases API 获取失败: {ex.Message}", LogHelper.LogType.Warning);
+            }
+            return (null, null, null);
+        }
+
         // 主要的更新检测方法（优先检测延迟，失败时自动切换线路组）
-        public static async Task<(string remoteVersion, UpdateLineGroup lineGroup)> CheckForUpdates(UpdateChannel channel = UpdateChannel.Release, bool alwaysGetRemote = false)
+        // 仅检测新版本时用GitHub API，实际下载时只用线路组
+        public static async Task<(string remoteVersion, UpdateLineGroup lineGroup, string releaseNotes)> CheckForUpdates(UpdateChannel channel = UpdateChannel.Release, bool alwaysGetRemote = false)
         {
             try
             {
                 string localVersion = Assembly.GetExecutingAssembly().GetName().Version.ToString();
                 LogHelper.WriteLogToFile($"AutoUpdate | 本地版本: {localVersion}");
-                LogHelper.WriteLogToFile($"AutoUpdate | 检测通道 {channel} 下最快线路组...");
-                
-                // 获取所有可用线路组（按延迟排序）
+                LogHelper.WriteLogToFile($"AutoUpdate | 优先通过GitHub Releases API检测...");
+                // 1. 优先通过GitHub Releases API获取
+                var (apiVersion, _, apiReleaseNotes) = await GetLatestGithubRelease(channel);
+                if (!string.IsNullOrEmpty(apiVersion))
+                {
+                    Version local = new Version(localVersion);
+                    Version remote = new Version(apiVersion.TrimStart('v', 'V'));
+                    if (remote > local || alwaysGetRemote)
+                    {
+                        LogHelper.WriteLogToFile($"AutoUpdate | 通过GitHub Releases API发现新版本: {apiVersion}");
+                        // 只返回版本号和日志，不返回直链
+                        var group = (await GetAvailableLineGroupsOrdered(channel)).FirstOrDefault();
+                        return (apiVersion, group, apiReleaseNotes);
+                    }
+                    else
+                    {
+                        LogHelper.WriteLogToFile($"AutoUpdate | 当前版本已是最新 (GitHub Releases API)");
+                        var group = (await GetAvailableLineGroupsOrdered(channel)).FirstOrDefault();
+                        return (null, group, apiReleaseNotes);
+                    }
+                }
+                // 2. 回退到原有txt方案
+                LogHelper.WriteLogToFile($"AutoUpdate | GitHub Releases API获取失败，回退到txt方案...");
                 var availableGroups = await GetAvailableLineGroupsOrdered(channel);
                 if (availableGroups.Count == 0)
                 {
                     LogHelper.WriteLogToFile("AutoUpdate | 所有线路组均不可用", LogHelper.LogType.Error);
-                    return (null, null);
+                    return (null, null, null);
                 }
-                
-                // 依次尝试每个线路组，直到成功获取版本信息
                 foreach (var group in availableGroups)
                 {
                     LogHelper.WriteLogToFile($"AutoUpdate | 尝试使用线路组获取版本信息: {group.GroupName}");
                     string remoteVersion = await GetRemoteVersion(group.VersionUrl);
-                    
                     if (remoteVersion != null)
                     {
                         LogHelper.WriteLogToFile($"AutoUpdate | 成功从线路组 {group.GroupName} 获取远程版本: {remoteVersion}");
                         Version local = new Version(localVersion);
                         Version remote = new Version(remoteVersion);
-                        
                         if (remote > local || alwaysGetRemote)
                         {
                             LogHelper.WriteLogToFile($"AutoUpdate | 发现新版本或强制获取: {remoteVersion}");
-                            return (remoteVersion, group);
+                            return (remoteVersion, group, null);
                         }
                         else
                         {
                             LogHelper.WriteLogToFile($"AutoUpdate | 当前版本已是最新");
-                            return (null, group);
+                            return (null, group, null);
                         }
                     }
                     else
@@ -387,14 +442,13 @@ namespace Ink_Canvas.Helpers
                         LogHelper.WriteLogToFile($"AutoUpdate | 线路组 {group.GroupName} 获取版本失败，尝试下一个线路组", LogHelper.LogType.Warning);
                     }
                 }
-                
                 LogHelper.WriteLogToFile("AutoUpdate | 所有线路组均无法获取版本信息", LogHelper.LogType.Error);
-                return (null, null);
+                return (null, null, null);
             }
             catch (Exception ex)
             {
                 LogHelper.WriteLogToFile($"AutoUpdate | CheckForUpdates错误: {ex.Message}", LogHelper.LogType.Error);
-                return (null, null);
+                return (null, null, null);
             }
         }
 
@@ -405,7 +459,7 @@ namespace Ink_Canvas.Helpers
         }
 
         // 使用多线路组下载新版（支持自动切换）
-        public static async Task<bool> DownloadSetupFileWithFallback(string version, List<UpdateLineGroup> groups)
+        public static async Task<bool> DownloadSetupFileWithFallback(string version, List<UpdateLineGroup> groups, Action<double, string> progressCallback = null)
         {
             try
             {
@@ -414,6 +468,7 @@ namespace Ink_Canvas.Helpers
                 if (File.Exists(statusFilePath) && File.ReadAllText(statusFilePath).Trim().ToLower() == "true")
                 {
                     LogHelper.WriteLogToFile("AutoUpdate | 安装包已下载");
+                    progressCallback?.Invoke(100, "已下载完成");
                     return true;
                 }
 
@@ -435,12 +490,13 @@ namespace Ink_Canvas.Helpers
                     string url = string.Format(group.DownloadUrlFormat, version);
                     LogHelper.WriteLogToFile($"AutoUpdate | 尝试从线路组 {group.GroupName} 下载: {url}");
                     
-                    bool downloadSuccess = await DownloadFile(url, zipFilePath);
+                    bool downloadSuccess = await DownloadFile(url, zipFilePath, progressCallback);
                     
                     if (downloadSuccess)
                     {
                         SaveDownloadStatus(true);
                         LogHelper.WriteLogToFile($"AutoUpdate | 从线路组 {group.GroupName} 下载成功");
+                        progressCallback?.Invoke(100, "下载完成");
                         return true;
                     }
                     else
@@ -450,6 +506,7 @@ namespace Ink_Canvas.Helpers
                 }
                 
                 LogHelper.WriteLogToFile("AutoUpdate | 所有线路组下载均失败", LogHelper.LogType.Error);
+                progressCallback?.Invoke(0, "所有线路组下载均失败");
                 return false;
             }
             catch (Exception ex)
@@ -461,283 +518,185 @@ namespace Ink_Canvas.Helpers
                 }
 
                 SaveDownloadStatus(false);
+                progressCallback?.Invoke(0, $"下载异常: {ex.Message}");
                 return false;
             }
         }
 
         // 下载文件的具体实现
-        private static async Task<bool> DownloadFile(string fileUrl, string destinationPath)
+        public static async Task<bool> DownloadFile(string fileUrl, string destinationPath, Action<double, string> progressCallback = null)
         {
-            // 检测是否为Windows 7
-            var osVersion = Environment.OSVersion;
-            bool isWindows7 = osVersion.Version.Major == 6 && osVersion.Version.Minor == 1;
-            
-            if (isWindows7)
+            LogHelper.WriteLogToFile($"AutoUpdate | 正在尝试多线程下载: {fileUrl}");
+            int maxRetry = 3;
+            int[] threadOptions = new int[] { 32, 4 };
+            foreach (int threadCount in threadOptions)
             {
-                // Windows 7使用特殊配置
-                using (var handler = new HttpClientHandler())
+                long totalSize = await GetContentLength(fileUrl);
+                if (totalSize <= 0)
                 {
-                    try
-                    {
-                        // 配置HttpClientHandler以支持Windows 7
-                        handler.ServerCertificateCustomValidationCallback = (sender, cert, chain, sslPolicyErrors) => true;
-                        
-                        using (HttpClient client = new HttpClient(handler))
-                        {
-                            client.Timeout = TimeSpan.FromMinutes(5);
-                            client.DefaultRequestHeaders.Add("User-Agent", "ICC-CE Auto Updater");
-                            
-                            LogHelper.WriteLogToFile($"AutoUpdate | 开始下载: {fileUrl}");
-                            
-                            string tempFilePath = destinationPath + ".tmp";
-                            
-                            string directory = Path.GetDirectoryName(destinationPath);
-                            if (!Directory.Exists(directory))
-                            {
-                                Directory.CreateDirectory(directory);
-                            }
-                            
-                            var downloadTask = client.GetAsync(fileUrl, HttpCompletionOption.ResponseHeadersRead);
-                            var initialTimeoutTask = Task.Delay(RequestTimeout);
-                            
-                            var completedTask = await Task.WhenAny(downloadTask, initialTimeoutTask);
-                            if (completedTask == initialTimeoutTask)
-                            {
-                                LogHelper.WriteLogToFile($"AutoUpdate | 初始连接超时", LogHelper.LogType.Error);
-                                return false;
-                            }
-                            
-                            HttpResponseMessage response = await downloadTask;
-                            LogHelper.WriteLogToFile($"AutoUpdate | HTTP响应状态: {response.StatusCode}");
-                            response.EnsureSuccessStatusCode();
-                            
-                            long? totalBytes = response.Content.Headers.ContentLength;
-                            LogHelper.WriteLogToFile($"AutoUpdate | 文件大小: {(totalBytes.HasValue ? (totalBytes.Value / 1024.0 / 1024.0).ToString("F2") + " MB" : "未知")}");
-                            
-                            using (var fileStream = new FileStream(tempFilePath, FileMode.Create, FileAccess.Write, FileShare.None))
-                            {
-                                using (var downloadStream = await response.Content.ReadAsStreamAsync())
-                                {
-                                    byte[] buffer = new byte[8192];
-                                    long totalBytesRead = 0;
-                                    int bytesRead;
-                                    DateTime lastProgressUpdate = DateTime.Now;
-                                    
-                                    var downloadTimeoutTask = Task.Delay(TimeSpan.FromSeconds(60));
-                                    var readTask = Task.Run(async () => {
-                                        while ((bytesRead = await downloadStream.ReadAsync(buffer, 0, buffer.Length)) > 0)
-                                        {
-                                            await fileStream.WriteAsync(buffer, 0, bytesRead);
-                                            totalBytesRead += bytesRead;
-                                            
-                                            if ((DateTime.Now - lastProgressUpdate).TotalSeconds >= 5)
-                                            {
-                                                if (totalBytes.HasValue)
-                                                {
-                                                    double percentage = (double)totalBytesRead / totalBytes.Value * 100;
-                                                    LogHelper.WriteLogToFile($"AutoUpdate | 下载进度: {percentage:F1}% ({(totalBytesRead / 1024.0 / 1024.0):F2} MB / {(totalBytes.Value / 1024.0 / 1024.0):F2} MB)");
-                                                }
-                                                else
-                                                {
-                                                    LogHelper.WriteLogToFile($"AutoUpdate | 已下载: {(totalBytesRead / 1024.0 / 1024.0):F2} MB");
-                                                }
-                                                lastProgressUpdate = DateTime.Now;
-                                                downloadTimeoutTask = Task.Delay(TimeSpan.FromSeconds(60));
-                                            }
-                                        }
-                                        return true;
-                                    });
-                                    
-                                    if (await Task.WhenAny(readTask, downloadTimeoutTask) == downloadTimeoutTask)
-                                    {
-                                        LogHelper.WriteLogToFile($"AutoUpdate | 下载超时（60秒无数据传输）", LogHelper.LogType.Error);
-                                        return false;
-                                    }
-                                    
-                                    bool downloadCompleted = await readTask;
-                                    
-                                    if (downloadCompleted)
-                                    {
-                                        LogHelper.WriteLogToFile($"AutoUpdate | 下载完成: {(totalBytesRead / 1024.0 / 1024.0):F2} MB");
-                                    }
-                                }
-                            }
-                            
-                            if (File.Exists(tempFilePath))
-                            {
-                                if (File.Exists(destinationPath))
-                                {
-                                    File.Delete(destinationPath);
-                                }
-                                
-                                File.Move(tempFilePath, destinationPath);
-                                LogHelper.WriteLogToFile($"AutoUpdate | 文件保存到: {destinationPath}");
-                                return true;
-                            }
-                            
-                            return false;
-                        }
-                    }
-                    catch (HttpRequestException ex)
-                    {
-                        LogHelper.WriteLogToFile($"AutoUpdate | HTTP请求错误: {ex.Message}", LogHelper.LogType.Error);
-                    }
-                    catch (TaskCanceledException ex)
-                    {
-                        LogHelper.WriteLogToFile($"AutoUpdate | 下载超时: {ex.Message}", LogHelper.LogType.Error);
-                    }
-                    catch (Exception ex)
-                    {
-                        LogHelper.WriteLogToFile($"AutoUpdate | 下载文件时出错: {ex.Message}", LogHelper.LogType.Error);
-                        if (ex.InnerException != null)
-                        {
-                            LogHelper.WriteLogToFile($"AutoUpdate | 内部异常: {ex.InnerException.Message}", LogHelper.LogType.Error);
-                        }
-                    }
-                    
-                    try
-                    {
-                        string tempFilePath = destinationPath + ".tmp";
-                        if (File.Exists(tempFilePath))
-                        {
-                            File.Delete(tempFilePath);
-                        }
-                    }
-                    catch { }
-                    
+                    progressCallback?.Invoke(0, "无法获取文件大小，取消下载");
                     return false;
                 }
-            }
-            else
-            {
-                // 其他Windows版本使用标准配置
-                using (HttpClient client = new HttpClient())
+                int blockSize = (int)Math.Ceiling((double)totalSize / threadCount);
+                int blockCount = (int)Math.Ceiling((double)totalSize / blockSize);
+                var blockQueue = new System.Collections.Concurrent.ConcurrentQueue<BlockTask>();
+                var finishedBlocks = new System.Collections.Concurrent.ConcurrentDictionary<int, bool>();
+                long[] blockDownloaded = new long[blockCount];
+                for (int i = 0; i < blockCount; i++)
                 {
-                    try
+                    long start = i * blockSize;
+                    long end = Math.Min(start + blockSize - 1, totalSize - 1);
+                    blockQueue.Enqueue(new BlockTask { Index = i, Start = start, End = end, RetryCount = 0 });
+                }
+                CancellationTokenSource cts = new CancellationTokenSource();
+                var tasks = new List<Task>();
+                for (int t = 0; t < threadCount; t++)
+                {
+                    tasks.Add(Task.Run(async () =>
                     {
-                        client.Timeout = TimeSpan.FromMinutes(5);
-                        client.DefaultRequestHeaders.Add("User-Agent", "ICC-CE Auto Updater");
-                        
-                        LogHelper.WriteLogToFile($"AutoUpdate | 开始下载: {fileUrl}");
-                        
-                        string tempFilePath = destinationPath + ".tmp";
-                        
-                        string directory = Path.GetDirectoryName(destinationPath);
-                        if (!Directory.Exists(directory))
+                        while (blockQueue.TryDequeue(out var block))
                         {
-                            Directory.CreateDirectory(directory);
-                        }
-                        
-                        var downloadTask = client.GetAsync(fileUrl, HttpCompletionOption.ResponseHeadersRead);
-                        var initialTimeoutTask = Task.Delay(RequestTimeout);
-                        
-                        var completedTask = await Task.WhenAny(downloadTask, initialTimeoutTask);
-                        if (completedTask == initialTimeoutTask)
-                        {
-                            LogHelper.WriteLogToFile($"AutoUpdate | 初始连接超时", LogHelper.LogType.Error);
-                            return false;
-                        }
-                        
-                        HttpResponseMessage response = await downloadTask;
-                        LogHelper.WriteLogToFile($"AutoUpdate | HTTP响应状态: {response.StatusCode}");
-                        response.EnsureSuccessStatusCode();
-                        
-                        long? totalBytes = response.Content.Headers.ContentLength;
-                        LogHelper.WriteLogToFile($"AutoUpdate | 文件大小: {(totalBytes.HasValue ? (totalBytes.Value / 1024.0 / 1024.0).ToString("F2") + " MB" : "未知")}");
-                        
-                        using (var fileStream = new FileStream(tempFilePath, FileMode.Create, FileAccess.Write, FileShare.None))
-                        {
-                            using (var downloadStream = await response.Content.ReadAsStreamAsync())
+                            bool success = false;
+                            for (int retry = block.RetryCount; retry < maxRetry && !success; retry++)
                             {
-                                byte[] buffer = new byte[8192];
-                                long totalBytesRead = 0;
-                                int bytesRead;
-                                DateTime lastProgressUpdate = DateTime.Now;
-                                
-                                var downloadTimeoutTask = Task.Delay(TimeSpan.FromSeconds(60));
-                                var readTask = Task.Run(async () => {
-                                    while ((bytesRead = await downloadStream.ReadAsync(buffer, 0, buffer.Length)) > 0)
+                                try
+                                {
+                                    using (var client = new HttpClient())
                                     {
-                                        await fileStream.WriteAsync(buffer, 0, bytesRead);
-                                        totalBytesRead += bytesRead;
-                                        
-                                        if ((DateTime.Now - lastProgressUpdate).TotalSeconds >= 5)
+                                        var req = new HttpRequestMessage(HttpMethod.Get, fileUrl);
+                                        req.Headers.Range = new System.Net.Http.Headers.RangeHeaderValue(block.Start, block.End);
+
+                                        // 新增：分块下载超时机制
+                                        var downloadCts = CancellationTokenSource.CreateLinkedTokenSource(cts.Token);
+                                        var lastReadTime = DateTime.UtcNow;
+                                        bool dataReceived = false;
+
+                                        using (var resp = await client.SendAsync(req, HttpCompletionOption.ResponseHeadersRead, downloadCts.Token))
                                         {
-                                            if (totalBytes.HasValue)
+                                            resp.EnsureSuccessStatusCode();
+                                            string tempPath = destinationPath + $".part{block.Index}";
+                                            using (var fs = new FileStream(tempPath, FileMode.Create, FileAccess.Write, FileShare.None))
                                             {
-                                                double percentage = (double)totalBytesRead / totalBytes.Value * 100;
-                                                LogHelper.WriteLogToFile($"AutoUpdate | 下载进度: {percentage:F1}% ({(totalBytesRead / 1024.0 / 1024.0):F2} MB / {(totalBytes.Value / 1024.0 / 1024.0):F2} MB)");
+                                                var stream = await resp.Content.ReadAsStreamAsync();
+                                                byte[] buffer = new byte[8192];
+                                                int read;
+                                                while (true)
+                                                {
+                                                    var readTask = stream.ReadAsync(buffer, 0, buffer.Length, downloadCts.Token);
+                                                    var timeoutTask = Task.Delay(15000, downloadCts.Token); // 15秒超时
+                                                    var completed = await Task.WhenAny(readTask, timeoutTask);
+                                                    if (completed == timeoutTask)
+                                                    {
+                                                        // 超时未收到数据，取消本线程，重新入队
+                                                        LogHelper.WriteLogToFile($"AutoUpdate | 分块{block.Index} 15秒无数据，线程超时重试", LogHelper.LogType.Warning);
+                                                        progressCallback?.Invoke(0, $"分块{block.Index} 15秒无数据，线程超时重试");
+                                                        downloadCts.Cancel();
+                                                        break;
+                                                    }
+                                                    read = await readTask;
+                                                    if (read <= 0) break;
+                                                    await fs.WriteAsync(buffer, 0, read, downloadCts.Token);
+                                                    blockDownloaded[block.Index] += read;
+                                                    lastReadTime = DateTime.UtcNow;
+                                                    dataReceived = true;
+                                                    // 合并所有块进度
+                                                    long totalDownloaded = blockDownloaded.Sum();
+                                                    double percent = (double)totalDownloaded / totalSize * 100;
+                                                    progressCallback?.Invoke(percent, $"多线程下载中({threadCount}线程): {percent:F1}%");
+                                                }
                                             }
-                                            else
-                                            {
-                                                LogHelper.WriteLogToFile($"AutoUpdate | 已下载: {(totalBytesRead / 1024.0 / 1024.0):F2} MB");
-                                            }
-                                            lastProgressUpdate = DateTime.Now;
-                                            downloadTimeoutTask = Task.Delay(TimeSpan.FromSeconds(60));
+                                        }
+                                        // 如果因超时break且未完成，success为false，重新入队
+                                        if (!dataReceived)
+                                        {
+                                            throw new IOException("分块下载超时无数据");
                                         }
                                     }
-                                    return true;
-                                });
-                                
-                                if (await Task.WhenAny(readTask, downloadTimeoutTask) == downloadTimeoutTask)
-                                {
-                                    LogHelper.WriteLogToFile($"AutoUpdate | 下载超时（60秒无数据传输）", LogHelper.LogType.Error);
-                                    return false;
+                                    success = true;
                                 }
-                                
-                                bool downloadCompleted = await readTask;
-                                
-                                if (downloadCompleted)
+                                catch (Exception ex) when (ex is HttpRequestException || ex is IOException || ex is TaskCanceledException)
                                 {
-                                    LogHelper.WriteLogToFile($"AutoUpdate | 下载完成: {(totalBytesRead / 1024.0 / 1024.0):F2} MB");
+                                    LogHelper.WriteLogToFile($"AutoUpdate | 分块{block.Index}下载失败，第{retry + 1}次: {ex.Message}", LogHelper.LogType.Warning);
+                                    progressCallback?.Invoke(0, $"分块{block.Index}下载失败，第{retry + 1}次: {ex.Message}");
+                                    await Task.Delay(15000);
                                 }
                             }
-                        }
-                        
-                        if (File.Exists(tempFilePath))
-                        {
-                            if (File.Exists(destinationPath))
+                            if (success)
                             {
-                                File.Delete(destinationPath);
+                                finishedBlocks[block.Index] = true;
+                            }
+                            else if (block.RetryCount + 1 < maxRetry)
+                            {
+                                // 失败但未超最大重试，重新入队
+                                block.RetryCount++;
+                                blockQueue.Enqueue(block);
+                            }
+                            else
+                            {
+                                // 超过最大重试，取消所有任务
+                                cts.Cancel();
+                                break;
                             }
-                            
-                            File.Move(tempFilePath, destinationPath);
-                            LogHelper.WriteLogToFile($"AutoUpdate | 文件保存到: {destinationPath}");
-                            return true;
                         }
-                        
+                    }));
+                }
+                await Task.WhenAll(tasks);
+                if (cts.IsCancellationRequested || finishedBlocks.Count != blockCount)
+                {
+                    progressCallback?.Invoke(0, $"多线程下载失败({threadCount}线程)");
+                    // 清理分块文件
+                    for (int i = 0; i < blockCount; i++)
+                    {
+                        string tempPath = destinationPath + $".part{i}";
+                        if (File.Exists(tempPath)) File.Delete(tempPath);
+                    }
+                    if (threadCount == threadOptions.Last())
+                    {
+                        // 已经是最后一次尝试
                         return false;
                     }
-                    catch (HttpRequestException ex)
+                    else
                     {
-                        LogHelper.WriteLogToFile($"AutoUpdate | HTTP请求错误: {ex.Message}", LogHelper.LogType.Error);
+                        LogHelper.WriteLogToFile($"AutoUpdate | {threadCount}线程下载失败，尝试降级为{threadOptions.Last()}线程");
+                        progressCallback?.Invoke(0, $"{threadCount}线程下载失败，尝试降级为{threadOptions.Last()}线程");
+                        continue;
                     }
-                    catch (TaskCanceledException ex)
+                }
+                // 合并所有块
+                using (var output = new FileStream(destinationPath, FileMode.Create, FileAccess.Write, FileShare.None))
+                {
+                    for (int i = 0; i < blockCount; i++)
                     {
-                        LogHelper.WriteLogToFile($"AutoUpdate | 下载超时: {ex.Message}", LogHelper.LogType.Error);
-                    }
-                    catch (Exception ex)
-                    {
-                        LogHelper.WriteLogToFile($"AutoUpdate | 下载文件时出错: {ex.Message}", LogHelper.LogType.Error);
-                        if (ex.InnerException != null)
+                        string tempPath = destinationPath + $".part{i}";
+                        using (var input = new FileStream(tempPath, FileMode.Open, FileAccess.Read))
                         {
-                            LogHelper.WriteLogToFile($"AutoUpdate | 内部异常: {ex.InnerException.Message}", LogHelper.LogType.Error);
+                            await input.CopyToAsync(output);
                         }
+                        File.Delete(tempPath);
                     }
-                    
-                    try
-                    {
-                        string tempFilePath = destinationPath + ".tmp";
-                        if (File.Exists(tempFilePath))
-                        {
-                            File.Delete(tempFilePath);
+                }
+                progressCallback?.Invoke(100, $"多线程下载完成({threadCount}线程)");
+                return true;
+            }
+            // 理论上不会到这里
+            return false;
+        }
+
+        // 获取文件总大小
+        private static async Task<long> GetContentLength(string fileUrl)
+        {
+            try
+            {
+                using (var client = new HttpClient())
+                {
+                    var req = new HttpRequestMessage(HttpMethod.Head, fileUrl);
+                    var resp = await client.SendAsync(req);
+                    if (resp.IsSuccessStatusCode && resp.Content.Headers.ContentLength.HasValue)
+                        return resp.Content.Headers.ContentLength.Value;
                         }
                     }
                     catch { }
-                    
-                    return false;
-                }
-            }
+            return -1;
         }
 
         // 保存下载状态
@@ -1065,7 +1024,7 @@ namespace Ink_Canvas.Helpers
                 LogHelper.WriteLogToFile($"AutoUpdate | 开始修复版本，通道: {channel}");
                 
                 // 获取远程版本号（自动选择最快线路组，始终下载远程版本）
-                var (remoteVersion, group) = await CheckForUpdates(channel, true);
+                var (remoteVersion, group, _) = await CheckForUpdates(channel, true);
                 if (string.IsNullOrEmpty(remoteVersion) || group == null)
                 {
                     LogHelper.WriteLogToFile("AutoUpdate | 修复版本时获取远程版本失败", LogHelper.LogType.Error);
@@ -1097,6 +1056,37 @@ namespace Ink_Canvas.Helpers
             }
         }
 
+        // 获取所有GitHub历史版本（Release）
+        public static async Task<List<(string version, string downloadUrl, string releaseNotes)>> GetAllGithubReleases(UpdateChannel channel = UpdateChannel.Release)
+        {
+            var result = new List<(string, string, string)>();
+            try
+            {
+                string apiUrl = channel == UpdateChannel.Beta
+                    ? "https://api.github.com/repos/InkCanvasForClass/community-beta/releases"
+                    : "https://api.github.com/repos/InkCanvasForClass/community/releases";
+                using (var client = new HttpClient())
+                {
+                    client.DefaultRequestHeaders.Add("User-Agent", "ICC-CE Auto Updater");
+                    var response = await client.GetStringAsync(apiUrl);
+                    var arr = JArray.Parse(response);
+                    foreach (var item in arr)
+                    {
+                        string version = item["tag_name"]?.ToString();
+                        string releaseNotes = item["body"]?.ToString();
+                        string downloadUrl = item["assets"]?.First?["browser_download_url"]?.ToString();
+                        if (!string.IsNullOrEmpty(version) && !string.IsNullOrEmpty(downloadUrl))
+                            result.Add((version, downloadUrl, releaseNotes));
+                    }
+                }
+            }
+            catch (Exception ex)
+            {
+                LogHelper.WriteLogToFile($"AutoUpdate | 获取历史版本失败: {ex.Message}", LogHelper.LogType.Error);
+            }
+            return result;
+        }
+
         // 测试Windows 7 TLS连接的方法
         public static async Task<bool> TestWindows7TlsConnection()
         {
@@ -1145,6 +1135,37 @@ namespace Ink_Canvas.Helpers
                 return false;
             }
         }
+
+        /// <summary>
+        /// 启动手动指定版本的多线路多线程下载并自动安装（用于历史版本回滚等场景）
+        /// </summary>
+        public static async Task<bool> StartManualDownloadAndInstall(string version, UpdateChannel channel, Action<double, string> progressCallback = null)
+        {
+            try
+            {
+                // 先检测并排序所有可用线路组
+                var groups = await GetAvailableLineGroupsOrdered(channel);
+                bool downloadSuccess = await DownloadSetupFileWithFallback(version, groups, progressCallback);
+                if (!downloadSuccess)
+                {
+                    LogHelper.WriteLogToFile($"AutoUpdate | 手动下载版本{version}失败");
+                    return false;
+                }
+                LogHelper.WriteLogToFile($"AutoUpdate | 手动安装版本: {version}");
+                InstallNewVersionApp(version, false);
+                App.IsAppExitByUser = true;
+                Application.Current.Dispatcher.Invoke(() => {
+                    Application.Current.Shutdown();
+                });
+                return true;
+            }
+            catch (Exception ex)
+            {
+                LogHelper.WriteLogToFile($"AutoUpdate | 手动下载或安装异常: {ex.Message}", LogHelper.LogType.Error);
+                progressCallback?.Invoke(0, $"下载异常: {ex.Message}");
+                return false;
+            }
+        }
     }
 
     internal class AutoUpdateWithSilenceTimeComboBox
diff --git a/Ink Canvas/MainWindow.xaml b/Ink Canvas/MainWindow.xaml
index 22fc9ca9..7882364b 100644
--- a/Ink Canvas/MainWindow.xaml	
+++ b/Ink Canvas/MainWindow.xaml	
@@ -645,8 +645,10 @@
                                             Width="120" HorizontalAlignment="Left" Click="FixVersionButton_Click"/>
                                     <TextBlock Text="# 版本修复会根据当前选择的通道下载最新版本并执行安装，可用于修复损坏的安装" 
                                                TextWrapping="Wrap" Foreground="#a1a1aa" />
-                                    
-                                    <Border BorderBrush="Black" BorderThickness="1" CornerRadius="5" Padding="12"
+                                    <Button x:Name="HistoryRollbackButton" Content="历史版本回滚" Width="120" Margin="0,10,0,0" Click="HistoryRollbackButton_Click"/>
+                                    <TextBlock Text="# 历史版本回滚，点击后会弹出相应页面供用户手动回滚到之前的版本" 
+                                               TextWrapping="Wrap" Foreground="#a1a1aa" />
+                                    <Border BorderBrush="White" BorderThickness="1" CornerRadius="5" Padding="12"
                                             Visibility="{Binding ElementName=ToggleSwitchIsAutoUpdateWithSilence, Path=IsOn, Converter={StaticResource BooleanToVisibilityConverter}}">
                                         <ui:SimpleStackPanel Spacing="12">
                                             <TextBlock
@@ -655,12 +657,12 @@
                                             <ui:SimpleStackPanel x:Name="AutoUpdateTimePeriodBlock" Spacing="12">
                                                 <ui:SimpleStackPanel Spacing="12">
                                                     <TextBlock Text="静默更新时间段" FontSize="15" FontWeight="Bold"
-                                                               TextWrapping="Wrap" Foreground="Black" />
+                                                               TextWrapping="Wrap" Foreground="#fafafa" />
                                                     <ui:SimpleStackPanel Orientation="Horizontal" Spacing="12">
                                                         <ui:SimpleStackPanel Orientation="Horizontal">
                                                             <TextBlock Margin="0,0,10,0" VerticalAlignment="Center"
                                                                        Text="起始时间" FontSize="14" TextWrapping="Wrap"
-                                                                       Foreground="Black" />
+                                                                       Foreground="#fafafa" />
                                                             <ComboBox x:Name="AutoUpdateWithSilenceStartTimeComboBox"
                                                                       Width="90"
                                                                       SelectionChanged="AutoUpdateWithSilenceStartTimeComboBox_SelectionChanged" />
@@ -668,7 +670,7 @@
                                                         <ui:SimpleStackPanel Orientation="Horizontal">
                                                             <TextBlock Margin="0,0,10,0" VerticalAlignment="Center"
                                                                        Text="终止时间" FontSize="14" TextWrapping="Wrap"
-                                                                       Foreground="Black" />
+                                                                       Foreground="#fafafa" />
                                                             <ComboBox x:Name="AutoUpdateWithSilenceEndTimeComboBox"
                                                                       Width="90"
                                                                       SelectionChanged="AutoUpdateWithSilenceEndTimeComboBox_SelectionChanged" />
@@ -849,6 +851,15 @@
                                     </ui:SimpleStackPanel>
                                     <TextBlock Text="# 允许选中墨迹后对墨迹进行双指或多指缩放操作（此设置不受“允许双指旋转”设置的影响）" TextWrapping="Wrap"
                                                Foreground="#a1a1aa" />
+                                    <Line HorizontalAlignment="Center" X1="0" Y1="0" X2="400" Y2="0" Stroke="#3f3f46"
+                                          StrokeThickness="1" Margin="0,4,0,4" />
+                                    <ui:SimpleStackPanel Orientation="Horizontal" HorizontalAlignment="Left">
+                                        <TextBlock Foreground="#fafafa" Text="启用手掌擦" VerticalAlignment="Center" FontSize="14" Margin="0,0,16,0" />
+                                        <ui:ToggleSwitch OnContent="" OffContent="" Name="ToggleSwitchEnablePalmEraser" IsOn="True"
+                                                         FontFamily="Microsoft YaHei UI" FontWeight="Bold"
+                                                         Toggled="ToggleSwitchEnablePalmEraser_Toggled" />
+                                    </ui:SimpleStackPanel>
+                                    <TextBlock Text="# 关闭后，手掌将无法触发橡皮擦功能" TextWrapping="Wrap" Foreground="#a1a1aa" />
                                 </ui:SimpleStackPanel>
                             </GroupBox>
                             <GroupBox Name="GroupBoxInkRecognition">
@@ -1206,6 +1217,7 @@
                                                          Toggled="ToggleSwitchEnableWppProcessKill_Toggled" />
                                     </ui:SimpleStackPanel>
                                     <TextBlock Text="# 关闭后将不会自动查杀WPP残留进程，可能导致WPP关闭卡顿或无法彻底退出。" TextWrapping="Wrap" Foreground="#a1a1aa" />
+                                    <TextBlock Text="# 如果您只使用PowerPoint请不要打开WPS联动开关，如果使用WPS建议不要使用PowerPoint！" TextWrapping="Wrap" Foreground="#a1a1aa" />
                                     <Border BorderBrush="#ef4444"
                                             BorderThickness="2" Padding="8" CornerRadius="6" Background="#991b1b">
                                         <ui:SimpleStackPanel Orientation="Horizontal" Spacing="4">
@@ -2888,7 +2900,7 @@
                     </ui:ScrollViewerEx>
                         
                         <!-- 底部按钮区域 -->
-                        <Grid Grid.Row="2" VerticalAlignment="Bottom" Height="50">
+                        <Grid Grid.Row="2" VerticalAlignment="Bottom" Height="65">
                             <Button FontFamily="Microsoft YaHei UI"
                                 Width="120" Margin="10"
                                 HorizontalAlignment="Right"
diff --git a/Ink Canvas/MainWindow.xaml.cs b/Ink Canvas/MainWindow.xaml.cs
index 3c035819..bf93374e 100644
--- a/Ink Canvas/MainWindow.xaml.cs	
+++ b/Ink Canvas/MainWindow.xaml.cs	
@@ -35,6 +35,14 @@ namespace Ink_Canvas {
         private static extern int GetWindowLong(IntPtr hWnd, int nIndex);
         private const int GWL_EXSTYLE = -20;
         private const int WS_EX_NOACTIVATE = 0x08000000;
+        [DllImport("user32.dll")]
+        private static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy, uint uFlags);
+        private static readonly IntPtr HWND_TOPMOST = new IntPtr(-1);
+        private static readonly IntPtr HWND_NOTOPMOST = new IntPtr(-2);
+        private const uint SWP_NOSIZE = 0x0001;
+        private const uint SWP_NOMOVE = 0x0002;
+        private const uint SWP_NOACTIVATE = 0x0010;
+        private const uint SWP_SHOWWINDOW = 0x0040;
         
         // 新增：设置窗口置顶并兼容无焦点
         private void SetTopmostWithNoActivate(bool topmost)
@@ -45,6 +53,15 @@ namespace Ink_Canvas {
             SetWindowLong(hwnd, GWL_EXSTYLE, exStyle & ~WS_EX_NOACTIVATE);
             // 设置 Topmost
             this.Topmost = topmost;
+            // 使用SetWindowPos确保无焦点置顶
+            if (topmost)
+            {
+                SetWindowPos(hwnd, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_NOACTIVATE | SWP_SHOWWINDOW);
+            }
+            else
+            {
+                SetWindowPos(hwnd, HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_NOACTIVATE | SWP_SHOWWINDOW);
+            }
             // 再加回 WS_EX_NOACTIVATE
             exStyle = GetWindowLong(hwnd, GWL_EXSTYLE);
             SetWindowLong(hwnd, GWL_EXSTYLE, exStyle | WS_EX_NOACTIVATE);
@@ -248,10 +265,25 @@ namespace Ink_Canvas {
             catch { }
         }
 
+        // 新增：记录上一个模式
+        private InkCanvasEditingMode lastEditingMode = InkCanvasEditingMode.Ink;
+
         private void inkCanvas_EditingModeChanged(object sender, RoutedEventArgs e) {
             var inkCanvas1 = sender as InkCanvas;
             if (inkCanvas1 == null) return;
 
+            // 只负责显示/隐藏覆盖层，不再强制切换模式
+            var eraserOverlay = this.FindName("AdvancedEraserOverlay") as Border;
+            if (eraserOverlay != null) {
+                if (inkCanvas1.EditingMode == InkCanvasEditingMode.EraseByPoint) {
+                    eraserOverlay.IsHitTestVisible = true;
+                    Trace.WriteLine("Advanced Eraser: Overlay enabled in eraser mode");
+                } else {
+                    eraserOverlay.IsHitTestVisible = false;
+                    DisableAdvancedEraserSystem();
+                    Trace.WriteLine("Advanced Eraser: Overlay disabled in non-eraser mode");
+                }
+            }
             // 使用辅助方法设置光标
             SetCursorBasedOnEditingMode(inkCanvas1);
             if (Settings.Canvas.IsShowCursor) {
@@ -262,31 +294,13 @@ namespace Ink_Canvas {
                 else
                     inkCanvas1.ForceCursor = false;
             } else {
-                // 套索选择模式下始终强制显示光标，即使用户设置不显示光标
                 if (inkCanvas1.EditingMode == InkCanvasEditingMode.Select) {
                     inkCanvas1.ForceCursor = true;
                 } else {
                     inkCanvas1.ForceCursor = false;
                 }
             }
-
             if (inkCanvas1.EditingMode == InkCanvasEditingMode.Ink) forcePointEraser = !forcePointEraser;
-            
-            // 处理高级橡皮擦覆盖层的启用/禁用
-            var eraserOverlay = this.FindName("AdvancedEraserOverlay") as Border;
-            if (eraserOverlay != null) {
-                if (inkCanvas1.EditingMode == InkCanvasEditingMode.EraseByPoint) {
-                    // 橡皮擦模式下启用覆盖层
-                    eraserOverlay.IsHitTestVisible = true;
-                    Trace.WriteLine("Advanced Eraser: Overlay enabled in eraser mode");
-                } else {
-                    // 其他模式下禁用覆盖层
-                    eraserOverlay.IsHitTestVisible = false;
-                    // 同时禁用高级橡皮擦系统
-                    DisableAdvancedEraserSystem();
-                    Trace.WriteLine("Advanced Eraser: Overlay disabled in non-eraser mode");
-                }
-            }
         }
 
         #endregion Ink Canvas
@@ -297,11 +311,16 @@ namespace Ink_Canvas {
         public static string settingsFileName = "Settings.json";
         private bool isLoaded = false;
         private bool forcePointEraser = false;
+        public static bool EnablePalmEraser = true;
 
         private void Window_Loaded(object sender, RoutedEventArgs e) {
             loadPenCanvas();
             //加载设置
             LoadSettings(true);
+            // 同步手掌擦开关
+            EnablePalmEraser = Settings.Canvas.EnablePalmEraser;
+            if (ToggleSwitchEnablePalmEraser != null)
+                ToggleSwitchEnablePalmEraser.IsOn = EnablePalmEraser;
             
             // 加载自定义背景颜色
             LoadCustomBackgroundColor();
@@ -381,6 +400,14 @@ namespace Ink_Canvas {
 
             // 初始化插件系统
             InitializePluginSystem();
+
+            // 新增：确保EditingModeChanged事件已绑定
+            var inkCanvas = this.FindName("inkCanvas") as InkCanvas;
+            if (inkCanvas != null)
+            {
+                inkCanvas.EditingModeChanged -= inkCanvas_EditingModeChanged;
+                inkCanvas.EditingModeChanged += inkCanvas_EditingModeChanged;
+            }
         }
 
         private void SystemEventsOnDisplaySettingsChanged(object sender, EventArgs e) {
@@ -535,7 +562,7 @@ namespace Ink_Canvas {
             AvailableLatestLineGroup = null;
             
             // 使用当前选择的更新通道检查更新
-            var (remoteVersion, lineGroup) = await AutoUpdateHelper.CheckForUpdates(Settings.Startup.UpdateChannel);
+            var (remoteVersion, lineGroup, apiReleaseNotes) = await AutoUpdateHelper.CheckForUpdates(Settings.Startup.UpdateChannel);
             AvailableLatestVersion = remoteVersion;
             AvailableLatestLineGroup = lineGroup;
             
@@ -1312,5 +1339,25 @@ namespace Ink_Canvas {
             // 直接调用PPT放映结束按钮的逻辑
             BtnPPTSlideShowEnd_Click(BtnPPTSlideShowEnd, null);
         }
+
+        private void HistoryRollbackButton_Click(object sender, RoutedEventArgs e)
+        {
+            // 收起设置面板（与插件面板一致）
+            BorderSettings.Visibility = Visibility.Hidden;
+            BorderSettingsMask.Visibility = Visibility.Hidden;
+            var win = new HistoryRollbackWindow(Settings.Startup.UpdateChannel);
+            win.ShowDialog();
+            // 可选：回滚窗口关闭后恢复设置面板显示
+            BorderSettings.Visibility = Visibility.Visible;
+            BorderSettingsMask.Visibility = Visibility.Visible;
+        }
+
+        private void ToggleSwitchEnablePalmEraser_Toggled(object sender, RoutedEventArgs e)
+        {
+            if (!isLoaded) return;
+            EnablePalmEraser = ToggleSwitchEnablePalmEraser.IsOn;
+            Settings.Canvas.EnablePalmEraser = EnablePalmEraser;
+            SaveSettingsToFile();
+        }
     }
 }
\ No newline at end of file
diff --git a/Ink Canvas/MainWindow_cs/MW_Eraser.cs b/Ink Canvas/MainWindow_cs/MW_Eraser.cs
index 0a16cb5c..d80b1a41 100644
--- a/Ink Canvas/MainWindow_cs/MW_Eraser.cs	
+++ b/Ink Canvas/MainWindow_cs/MW_Eraser.cs	
@@ -634,52 +634,68 @@ namespace Ink_Canvas {
                 
                 // 绑定事件处理
                 overlay.MouseDown += (sender, e) => {
+                    if (!MainWindow.EnablePalmEraser) return;
+                    var inkCanvas = this.FindName("inkCanvas") as InkCanvas;
                     if (inkCanvas.EditingMode == InkCanvasEditingMode.EraseByPoint) {
+                        lastEditingMode = inkCanvas.EditingMode;
                         overlay.CaptureMouse();
+                        inkCanvas.EditingMode = InkCanvasEditingMode.None;
                         StartAdvancedEraserOperation(sender);
                     }
                 };
                 
                 overlay.MouseUp += (sender, e) => {
-                    if (inkCanvas.EditingMode == InkCanvasEditingMode.EraseByPoint) {
+                    if (!MainWindow.EnablePalmEraser) return;
+                    var inkCanvas = this.FindName("inkCanvas") as InkCanvas;
+                    if (inkCanvas.EditingMode == InkCanvasEditingMode.None) {
                         overlay.ReleaseMouseCapture();
                         EndAdvancedEraserOperation(sender);
+                        inkCanvas.EditingMode = InkCanvasEditingMode.Ink; // 抬手后自动回到画笔
                     }
                 };
                 
                 overlay.MouseMove += (sender, e) => {
-                    if (inkCanvas.EditingMode == InkCanvasEditingMode.EraseByPoint) {
+                    if (!MainWindow.EnablePalmEraser) return;
+                    var inkCanvas = this.FindName("inkCanvas") as InkCanvas;
+                    if (inkCanvas.EditingMode == InkCanvasEditingMode.None) {
                         var position = e.GetPosition((UIElement)this.FindName("inkCanvas"));
                         Trace.WriteLine($"Advanced Eraser: Mouse move event triggered at ({position.X:F1}, {position.Y:F1})");
                         UpdateAdvancedEraserPosition(sender, position);
-                    } else {
-                        Trace.WriteLine($"Advanced Eraser: Mouse move ignored - not in eraser mode, current mode: {inkCanvas.EditingMode}");
                     }
                 };
                 
                 // 触控笔事件
                 overlay.StylusDown += (sender, e) => {
+                    if (!MainWindow.EnablePalmEraser) return;
+                    var inkCanvas = this.FindName("inkCanvas") as InkCanvas;
                     if (inkCanvas.EditingMode == InkCanvasEditingMode.EraseByPoint) {
                         e.Handled = true;
                         if (e.StylusDevice.TabletDevice.Type == TabletDeviceType.Stylus) {
                             overlay.CaptureStylus();
                         }
+                        lastEditingMode = inkCanvas.EditingMode;
+                        inkCanvas.EditingMode = InkCanvasEditingMode.None;
                         StartAdvancedEraserOperation(sender);
                     }
                 };
                 
                 overlay.StylusUp += (sender, e) => {
-                    if (inkCanvas.EditingMode == InkCanvasEditingMode.EraseByPoint) {
+                    if (!MainWindow.EnablePalmEraser) return;
+                    var inkCanvas = this.FindName("inkCanvas") as InkCanvas;
+                    if (inkCanvas.EditingMode == InkCanvasEditingMode.None) {
                         e.Handled = true;
                         if (e.StylusDevice.TabletDevice.Type == TabletDeviceType.Stylus) {
                             overlay.ReleaseStylusCapture();
                         }
                         EndAdvancedEraserOperation(sender);
+                        inkCanvas.EditingMode = InkCanvasEditingMode.Ink; // 抬手后自动回到画笔
                     }
                 };
                 
                 overlay.StylusMove += (sender, e) => {
-                    if (inkCanvas.EditingMode == InkCanvasEditingMode.EraseByPoint) {
+                    if (!MainWindow.EnablePalmEraser) return;
+                    var inkCanvas = this.FindName("inkCanvas") as InkCanvas;
+                    if (inkCanvas.EditingMode == InkCanvasEditingMode.None) {
                         e.Handled = true;
                         var position = e.GetPosition((UIElement)this.FindName("inkCanvas"));
                         UpdateAdvancedEraserPosition(sender, position);
diff --git a/Ink Canvas/MainWindow_cs/MW_Timer.cs b/Ink Canvas/MainWindow_cs/MW_Timer.cs
index 262126c4..30436a85 100644
--- a/Ink Canvas/MainWindow_cs/MW_Timer.cs	
+++ b/Ink Canvas/MainWindow_cs/MW_Timer.cs	
@@ -9,6 +9,9 @@ using System.IO;
 using System.Reflection;
 using System.Threading.Tasks;
 using System.Windows.Controls;
+using System.Net;
+using System.Net.Sockets;
+using System.Linq;
 
 namespace Ink_Canvas {
     public class TimeViewModel : INotifyPropertyChanged {
@@ -55,6 +58,35 @@ namespace Ink_Canvas {
 
         private TimeViewModel nowTimeVM = new TimeViewModel();
 
+        private async Task<DateTime> GetNetworkTimeAsync()
+        {
+            try
+            {
+                const string ntpServer = "ntp.ntsc.ac.cn";
+                var ntpData = new byte[48];
+                ntpData[0] = 0x1B;
+                var addresses = await Dns.GetHostAddressesAsync(ntpServer);
+                var ipEndPoint = new IPEndPoint(addresses[0], 123);
+                using (var socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp))
+                {
+                    socket.ReceiveTimeout = 2000;
+                    socket.Connect(ipEndPoint);
+                    await Task.Factory.FromAsync(socket.BeginSend(ntpData, 0, ntpData.Length, SocketFlags.None, null, socket), socket.EndSend);
+                    await Task.Factory.FromAsync(socket.BeginReceive(ntpData, 0, ntpData.Length, SocketFlags.None, null, socket), socket.EndReceive);
+                }
+                const byte serverReplyTime = 40;
+                ulong intPart = BitConverter.ToUInt32(ntpData.Skip(serverReplyTime).Take(4).Reverse().ToArray(), 0);
+                ulong fractPart = BitConverter.ToUInt32(ntpData.Skip(serverReplyTime + 4).Take(4).Reverse().ToArray(), 0);
+                var milliseconds = (intPart * 1000) + ((fractPart * 1000) / 0x100000000L);
+                var networkDateTime = (new DateTime(1900, 1, 1)).AddMilliseconds((long)milliseconds);
+                return networkDateTime.ToLocalTime();
+            }
+            catch
+            {
+                return DateTime.Now;
+            }
+        }
+
         private void InitTimers() {
             timerCheckPPT.Elapsed += TimerCheckPPT_Elapsed;
             timerCheckPPT.Interval = 500;
@@ -66,7 +98,7 @@ namespace Ink_Canvas {
             timerCheckAutoUpdateWithSilence.Interval = 1000 * 60 * 10;
             WaterMarkTime.DataContext = nowTimeVM;
             WaterMarkDate.DataContext = nowTimeVM;
-            timerDisplayTime.Elapsed += TimerDisplayTime_Elapsed;
+            timerDisplayTime.Elapsed += async (s, e) => await TimerDisplayTime_ElapsedAsync();
             timerDisplayTime.Interval = 1000;
             timerDisplayTime.Start();
             timerDisplayDate.Elapsed += TimerDisplayDate_Elapsed;
@@ -77,8 +109,14 @@ namespace Ink_Canvas {
             nowTimeVM.nowTime = DateTime.Now.ToShortTimeString().ToString();
         }
 
-        private void TimerDisplayTime_Elapsed(object sender, ElapsedEventArgs e) {
-            nowTimeVM.nowTime = DateTime.Now.ToShortTimeString().ToString();
+        private async Task TimerDisplayTime_ElapsedAsync()
+        {
+            DateTime now = await GetNetworkTimeAsync();
+            // 只更新时间，日期由原有逻辑定时更新即可
+            Dispatcher.Invoke(() =>
+            {
+                nowTimeVM.nowTime = now.ToShortTimeString();
+            });
         }
 
         private void TimerDisplayDate_Elapsed(object sender, ElapsedEventArgs e) {
diff --git a/Ink Canvas/Properties/AssemblyInfo.cs b/Ink Canvas/Properties/AssemblyInfo.cs
index da30cbb4..71637f68 100644
--- a/Ink Canvas/Properties/AssemblyInfo.cs	
+++ b/Ink Canvas/Properties/AssemblyInfo.cs	
@@ -49,5 +49,5 @@ using System.Windows;
 // You can specify all the values or you can default the Build and Revision Numbers
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("1.7.1.10")]
-[assembly: AssemblyFileVersion("1.7.1.10")]
+[assembly: AssemblyVersion("1.7.1.12")]
+[assembly: AssemblyFileVersion("1.7.1.12")]
diff --git a/Ink Canvas/Resources/Settings.cs b/Ink Canvas/Resources/Settings.cs
index 32a6a9eb..f55bc913 100644
--- a/Ink Canvas/Resources/Settings.cs	
+++ b/Ink Canvas/Resources/Settings.cs	
@@ -77,6 +77,8 @@ namespace Ink_Canvas
         public OptionalOperation HyperbolaAsymptoteOption { get; set; } = OptionalOperation.Ask;
         [JsonProperty("isCompressPicturesUploaded")]
         public bool IsCompressPicturesUploaded { get; set; } = false;
+        [JsonProperty("enablePalmEraser")]
+        public bool EnablePalmEraser { get; set; } = true;
     }
 
     public enum OptionalOperation
diff --git a/Ink Canvas/Windows/HasNewUpdateWindow.xaml b/Ink Canvas/Windows/HasNewUpdateWindow.xaml
index c190e9ba..61d8f5d9 100644
--- a/Ink Canvas/Windows/HasNewUpdateWindow.xaml	
+++ b/Ink Canvas/Windows/HasNewUpdateWindow.xaml	
@@ -78,6 +78,12 @@
                                 Background="#f8fafc" BorderBrush="#cbd5e1" ToolTip="跳过此版本更新" Visibility="Visible" IsEnabled="True"/>
                     </ui:SimpleStackPanel>
                                 </Border>
+
+                <!-- 下载进度条和状态 -->
+                <StackPanel x:Name="DownloadProgressPanel" Orientation="Vertical" HorizontalAlignment="Center" Margin="0,10,0,0" Visibility="Collapsed">
+                    <ProgressBar x:Name="DownloadProgressBar" Width="360" Height="18" Minimum="0" Maximum="100" Value="0"/>
+                    <TextBlock x:Name="DownloadProgressText" Text="正在下载..." FontSize="14" Foreground="#2563eb" HorizontalAlignment="Center" Margin="0,6,0,0"/>
+                </StackPanel>
             </ui:SimpleStackPanel>
         </Grid>
     </ScrollViewer>
diff --git a/Ink Canvas/Windows/HasNewUpdateWindow.xaml.cs b/Ink Canvas/Windows/HasNewUpdateWindow.xaml.cs
index 7548e423..c3f4b598 100644
--- a/Ink Canvas/Windows/HasNewUpdateWindow.xaml.cs	
+++ b/Ink Canvas/Windows/HasNewUpdateWindow.xaml.cs	
@@ -7,6 +7,9 @@ using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Interop;
 using System.Windows.Media;
+using System.Threading.Tasks;
+using System.IO;
+using System.Threading;
 
 namespace Ink_Canvas
 {
@@ -129,16 +132,59 @@ namespace Ink_Canvas
             LogHelper.WriteLogToFile("AutoUpdate | Update dialog buttons visibility ensured");
         }
 
-        private void UpdateNowButton_Click(object sender, RoutedEventArgs e)
+        private async void UpdateNowButton_Click(object sender, RoutedEventArgs e)
         {
             LogHelper.WriteLogToFile("AutoUpdate | Update Now button clicked");
-            
+            // 禁用按钮，显示进度条
+            UpdateNowButton.IsEnabled = false;
+            UpdateLaterButton.IsEnabled = false;
+            SkipVersionButton.IsEnabled = false;
+            DownloadProgressPanel.Visibility = Visibility.Visible;
+            DownloadProgressBar.Value = 0;
+            DownloadProgressText.Text = "正在准备下载...";
+
+            // 启动多线路下载
+            bool downloadSuccess = false;
+            try
+            {
+                // 获取当前通道的所有线路组
+                var groups = AutoUpdateHelper.ChannelLineGroups[MainWindow.Settings.Startup.UpdateChannel];
+                downloadSuccess = await AutoUpdateHelper.DownloadSetupFileWithFallback(NewVersion, groups, (percent, text) =>
+                {
+                    Dispatcher.Invoke(() => {
+                        DownloadProgressBar.Value = percent;
+                        DownloadProgressText.Text = text;
+                    });
+                });
+                if (downloadSuccess)
+                {
+                    // 下载完成后自动安装
+                    await DownloadAndInstallVersion(NewVersion, null, CancellationToken.None);
+                }
+            }
+            catch (Exception ex)
+            {
+                DownloadProgressText.Text = $"下载失败: {ex.Message}";
+                LogHelper.WriteLogToFile($"AutoUpdate | 下载异常: {ex.Message}", LogHelper.LogType.Error);
+            }
+
+            if (downloadSuccess)
+            {
+                DownloadProgressBar.Value = 100;
+                DownloadProgressText.Text = "下载完成，准备安装...";
+                await Task.Delay(800);
             // 设置结果为立即更新
             Result = UpdateResult.UpdateNow;
-            
-            // 关闭窗口，返回到MainWindow处理后续下载和安装流程
             DialogResult = true;
             Close();
+            }
+            else
+            {
+                DownloadProgressText.Text = "下载失败，请检查网络后重试。";
+                UpdateNowButton.IsEnabled = true;
+                UpdateLaterButton.IsEnabled = true;
+                SkipVersionButton.IsEnabled = true;
+            }
         }
 
         private void UpdateLaterButton_Click(object sender, RoutedEventArgs e)
@@ -279,5 +325,23 @@ namespace Ink_Canvas
                 }
             }
         }
+
+        // 多线程分块下载并自动安装
+        private async Task<bool> DownloadAndInstallVersion(string version, string downloadUrl, CancellationToken token)
+        {
+            if (string.IsNullOrEmpty(downloadUrl))
+            {
+                // 自动更新场景下，downloadUrl为null，直接用主下载目录
+                string updatesFolderPath = Path.Combine(Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location), "AutoUpdate");
+                downloadUrl = Path.Combine(updatesFolderPath, $"InkCanvasForClass.CE.{version}.zip");
+            }
+            LogHelper.WriteLogToFile($"AutoUpdate | 开始安装版本: {version}");
+            AutoUpdateHelper.InstallNewVersionApp(version, false);
+            App.IsAppExitByUser = true;
+            Application.Current.Dispatcher.Invoke(() => {
+                Application.Current.Shutdown();
+            });
+            return true;
+        }
     }
 }
diff --git a/Ink Canvas/Windows/HistoryRollbackWindow.xaml b/Ink Canvas/Windows/HistoryRollbackWindow.xaml
new file mode 100644
index 00000000..ce811560
--- /dev/null
+++ b/Ink Canvas/Windows/HistoryRollbackWindow.xaml	
@@ -0,0 +1,24 @@
+<Window x:Class="Ink_Canvas.HistoryRollbackWindow"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        xmlns:ui="http://schemas.inkore.net/lib/ui/wpf/modern"
+        xmlns:mdxam="clr-namespace:MdXaml;assembly=MdXaml"
+        mc:Ignorable="d"
+        Title="历史版本回滚" Height="600" Width="850" ResizeMode="NoResize" WindowStartupLocation="CenterScreen">
+    <Grid Background="#fafafa">
+        <ui:SimpleStackPanel VerticalAlignment="Stretch" Spacing="0">
+            <TextBlock Text="选择历史版本进行回滚" FontSize="24" FontWeight="Bold" Foreground="#2563eb" Margin="24,24,0,12"/>
+            <ComboBox x:Name="VersionComboBox" Width="400" Height="36" Margin="24,0,0,0" DisplayMemberPath="Version" SelectionChanged="VersionComboBox_SelectionChanged"/>
+            <Border BorderBrush="#3f3f46" Background="White" BorderThickness="1" CornerRadius="4" Margin="24,16,24,0" Height="180">
+                <mdxam:MarkdownScrollViewer x:Name="ReleaseNotesViewer" Foreground="Black" MarkdownStyleName="GithubLike"/>
+            </Border>
+            <Button x:Name="RollbackButton" Content="回滚到此版本" Width="360" Height="48" Margin="24,24,0,0" Click="RollbackButton_Click"/>
+            <StackPanel x:Name="DownloadProgressPanel" Orientation="Vertical" HorizontalAlignment="Center" Margin="0,10,0,0" Visibility="Collapsed">
+                <ProgressBar x:Name="DownloadProgressBar" Width="360" Height="18" Minimum="0" Maximum="100" Value="0"/>
+                <TextBlock x:Name="DownloadProgressText" Text="正在下载..." FontSize="14" Foreground="#2563eb" HorizontalAlignment="Center" Margin="0,6,0,0"/>
+            </StackPanel>
+        </ui:SimpleStackPanel>
+    </Grid>
+</Window> 
\ No newline at end of file
diff --git a/Ink Canvas/Windows/HistoryRollbackWindow.xaml.cs b/Ink Canvas/Windows/HistoryRollbackWindow.xaml.cs
new file mode 100644
index 00000000..88621545
--- /dev/null
+++ b/Ink Canvas/Windows/HistoryRollbackWindow.xaml.cs	
@@ -0,0 +1,142 @@
+using Ink_Canvas.Helpers;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Input;
+using System.Linq; // Added for OrderByDescending
+using System.ComponentModel;
+using System.Threading;
+
+namespace Ink_Canvas
+{
+    public partial class HistoryRollbackWindow : Window
+    {
+        private class VersionItem
+        {
+            public string Version { get; set; }
+            public string DownloadUrl { get; set; }
+            public string ReleaseNotes { get; set; }
+        }
+
+        private List<VersionItem> versionList = new List<VersionItem>();
+        private VersionItem selectedItem = null;
+        private UpdateChannel channel = UpdateChannel.Release;
+        private CancellationTokenSource downloadCts = null;
+
+        public HistoryRollbackWindow(UpdateChannel channel = UpdateChannel.Release)
+        {
+            InitializeComponent();
+            this.channel = channel;
+            LoadVersions();
+        }
+
+        private async void LoadVersions()
+        {
+            LogHelper.WriteLogToFile($"HistoryRollback | 开始加载历史版本，通道: {channel}");
+            RollbackButton.IsEnabled = false;
+            VersionComboBox.Items.Clear();
+            DownloadProgressPanel.Visibility = Visibility.Collapsed;
+            DownloadProgressBar.Value = 0;
+            DownloadProgressText.Text = "";
+            ReleaseNotesViewer.Markdown = "正在获取历史版本...";
+            var releases = await AutoUpdateHelper.GetAllGithubReleases(channel);
+            versionList.Clear();
+            foreach (var (version, url, notes) in releases)
+            {
+                versionList.Add(new VersionItem { Version = version, DownloadUrl = url, ReleaseNotes = notes });
+            }
+            // 按版本号数字降序排列
+            versionList = versionList.OrderByDescending(v => ParseVersionForSort(v.Version)).ToList();
+            VersionComboBox.ItemsSource = versionList;
+            if (versionList.Count > 0)
+            {
+                VersionComboBox.SelectedIndex = 0;
+                RollbackButton.IsEnabled = true;
+                LogHelper.WriteLogToFile($"HistoryRollback | 加载到 {versionList.Count} 个历史版本");
+            }
+            else
+            {
+                ReleaseNotesViewer.Markdown = "未获取到历史版本信息。";
+                LogHelper.WriteLogToFile($"HistoryRollback | 未获取到历史版本信息", LogHelper.LogType.Warning);
+            }
+        }
+
+        // 辅助方法：解析版本号用于排序
+        private Version ParseVersionForSort(string version)
+        {
+            var v = version.TrimStart('v', 'V');
+            Version result;
+            if (Version.TryParse(v, out result))
+                return result;
+            return new Version(0, 0, 0, 0);
+        }
+
+        private void VersionComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
+        {
+            selectedItem = VersionComboBox.SelectedItem as VersionItem;
+            if (selectedItem != null)
+            {
+                ReleaseNotesViewer.Markdown = selectedItem.ReleaseNotes ?? "无更新日志";
+                LogHelper.WriteLogToFile($"HistoryRollback | 用户选择版本: {selectedItem.Version}");
+            }
+            // 取消聚焦，防止父级自动滚动
+            Keyboard.ClearFocus();
+        }
+
+        private async void RollbackButton_Click(object sender, RoutedEventArgs e)
+        {
+            if (selectedItem == null) return;
+            LogHelper.WriteLogToFile($"HistoryRollback | 用户点击回滚，目标版本: {selectedItem.Version}");
+            RollbackButton.IsEnabled = false;
+            VersionComboBox.IsEnabled = false;
+            DownloadProgressPanel.Visibility = Visibility.Visible;
+            DownloadProgressBar.Value = 0;
+            DownloadProgressText.Text = "正在准备下载...";
+
+            bool downloadSuccess = false;
+            try
+            {
+                downloadSuccess = await AutoUpdateHelper.StartManualDownloadAndInstall(
+                    selectedItem.Version,
+                    channel,
+                    (percent, text) =>
+                    {
+                        Dispatcher.Invoke(() => {
+                            DownloadProgressBar.Value = percent;
+                            DownloadProgressText.Text = text;
+                        });
+                    }
+                );
+            }
+            catch (Exception ex)
+            {
+                DownloadProgressText.Text = $"下载失败: {ex.Message}";
+                LogHelper.WriteLogToFile($"HistoryRollback | 下载异常: {ex.Message}", LogHelper.LogType.Error);
+            }
+
+            if (downloadSuccess)
+            {
+                DownloadProgressBar.Value = 100;
+                DownloadProgressText.Text = "下载完成，准备安装...";
+                await Task.Delay(800);
+                this.DialogResult = true;
+                this.Close();
+            }
+            else
+            {
+                DownloadProgressText.Text = "下载失败，请检查网络后重试。";
+                RollbackButton.IsEnabled = true;
+                VersionComboBox.IsEnabled = true;
+            }
+        }
+
+        protected override void OnClosing(CancelEventArgs e)
+        {
+            downloadCts?.Cancel();
+            base.OnClosing(e);
+        }
+    }
+} 
\ No newline at end of file
diff --git a/Ink Canvas/obj/Debug/net472/InkCanvasForClass_MarkupCompile.cache b/Ink Canvas/obj/Debug/net472/InkCanvasForClass_MarkupCompile.cache
index f4d9f6d1..9faa8f50 100644
--- a/Ink Canvas/obj/Debug/net472/InkCanvasForClass_MarkupCompile.cache	
+++ b/Ink Canvas/obj/Debug/net472/InkCanvasForClass_MarkupCompile.cache	
@@ -10,11 +10,11 @@ none
 false
 TRACE;DEBUG;NETFRAMEWORK;NET472;;NET30_OR_GREATER;NET35_OR_GREATER;NET40_OR_GREATER;NET45_OR_GREATER;NET451_OR_GREATER;NET452_OR_GREATER;NET46_OR_GREATER;NET461_OR_GREATER;NET462_OR_GREATER;NET47_OR_GREATER;NET471_OR_GREATER;NET472_OR_GREATER
 E:\ICC CE\ICC CE main\community\Ink Canvas\App.xaml
-21348134359
+22-2143008179
 
-752071346691
+76-141727233
 471037513499
-Helpers\Plugins\BuiltIn\SuperLauncher\LauncherSettingsControl.xaml;Helpers\Plugins\BuiltIn\SuperLauncher\LauncherWindow.xaml;MainWindow.xaml;MainWindow_cs\MW_Eraser.xaml;Resources\DrawShapeImageDictionary.xaml;Resources\IconImageDictionary.xaml;Resources\SeewoImageDictionary.xaml;Resources\Styles\Dark.xaml;Resources\Styles\Light.xaml;Windows\AddCustomIconWindow.xaml;Windows\AddPickNameBackgroundWindow.xaml;Windows\CountdownTimerWindow.xaml;Windows\CustomIconWindow.xaml;Windows\CycleProcessBar.xaml;Windows\HasNewUpdateWindow.xaml;Windows\ManagePickNameBackgroundsWindow.xaml;Windows\NamesInputWindow.xaml;Windows\OperatingGuideWindow.xaml;Windows\PluginSettingsWindow.xaml;Windows\RandWindow.xaml;Windows\YesOrNoNotificationWindow.xaml;
+Helpers\Plugins\BuiltIn\SuperLauncher\LauncherSettingsControl.xaml;Helpers\Plugins\BuiltIn\SuperLauncher\LauncherWindow.xaml;MainWindow.xaml;MainWindow_cs\MW_Eraser.xaml;Resources\DrawShapeImageDictionary.xaml;Resources\IconImageDictionary.xaml;Resources\SeewoImageDictionary.xaml;Resources\Styles\Dark.xaml;Resources\Styles\Light.xaml;Windows\AddCustomIconWindow.xaml;Windows\AddPickNameBackgroundWindow.xaml;Windows\CountdownTimerWindow.xaml;Windows\CustomIconWindow.xaml;Windows\CycleProcessBar.xaml;Windows\HasNewUpdateWindow.xaml;Windows\HistoryRollbackWindow.xaml;Windows\ManagePickNameBackgroundsWindow.xaml;Windows\NamesInputWindow.xaml;Windows\OperatingGuideWindow.xaml;Windows\PluginSettingsWindow.xaml;Windows\RandWindow.xaml;Windows\YesOrNoNotificationWindow.xaml;
 
 False