feat: 浮动栏截图修改为选区截图，添加“添加到白板”按钮 (#377)

* 调整截图按钮默认行为为选区/白板全屏

* 截图选择器新增添加到白板按钮并支持新建白板页插入

* 修复添加到白板不生效：改为剪贴板复制粘贴插入

* 修复添加到白板截图时序：先截到内存再进白板

* Fix screenshot insert flow honoring add-to-whiteboard option

* Refine screenshot selector freehand confirm and blank double-click full select

* Fix freehand whiteboard insert alpha transparency

* Fix screenshot insert notification text for whiteboard flow

* Adjust screenshot selection: right-click/double-click full-select and keep selector on single click

* Show unmasked freehand selection area like rectangle mode

* Remove freehand cutout mask rendering from screenshot selector

* Restore freehand selected-area unmask behavior in selector

Ink Canvas/MainWindow_cs/MW_FloatingBarIcons.cs

@@ -1130,7 +1130,16 @@ namespace Ink_Canvas
         {
             HideSubPanelsImmediately();
             await Task.Delay(50);
-            SaveScreenShotToDesktop();
+
+            // 白板模式下默认全屏截图到桌面；其余模式默认调用可选区截图
+            if (currentMode == 1)
+            {
+                SaveScreenShotToDesktop();
+            }
+            else
+            {
+                await SaveAreaScreenShotToDesktop();
+            }
         }
 
         /// <summary>
@@ -4309,4 +4318,4 @@ namespace Ink_Canvas
         }
 
     }
-}
+}

Ink Canvas/MainWindow_cs/MW_ImageInsert.cs

@@ -29,13 +29,16 @@ namespace Ink_Canvas
         public List<Point> Path;
         public Bitmap CameraImage;
         public BitmapSource CameraBitmapSource;
+        public bool AddToWhiteboard;
 
-        public ScreenshotResult(Rectangle area, List<Point> path = null, Bitmap cameraImage = null, BitmapSource cameraBitmapSource = null)
+        public ScreenshotResult(Rectangle area, List<Point> path = null, Bitmap cameraImage = null,
+            BitmapSource cameraBitmapSource = null, bool addToWhiteboard = false)
         {
             Area = area;
             Path = path;
             CameraImage = cameraImage;
             CameraBitmapSource = cameraBitmapSource;
+            AddToWhiteboard = addToWhiteboard;
         }
     }
 
@@ -72,11 +75,17 @@ namespace Ink_Canvas
 
                 if (screenshotResult.HasValue)
                 {
+                    if (screenshotResult.Value.AddToWhiteboard)
+                    {
+                        await AddScreenshotToNewWhiteboardPage(screenshotResult.Value);
+                        return;
+                    }
+
                     // 检查是否是摄像头截图
                     if (screenshotResult.Value.CameraBitmapSource != null)
                     {
                         // 摄像头截图（使用BitmapSource）
-                        await InsertBitmapSourceToCanvas(screenshotResult.Value.CameraBitmapSource);
+                        await InsertBitmapSourceToCanvas(screenshotResult.Value.CameraBitmapSource, "摄像头截图已插入到画布", "插入摄像头截图失败");
                     }
                     else if (screenshotResult.Value.CameraImage != null)
                     {
@@ -208,7 +217,8 @@ namespace Ink_Canvas
                                 Rectangle.Empty, // 摄像头截图不需要区域
                                 null, // 摄像头截图不需要路径
                                 null, // 不再使用Bitmap
-                                selectorWindow.CameraBitmapSource // 摄像头BitmapSource
+                                selectorWindow.CameraBitmapSource, // 摄像头BitmapSource
+                                selectorWindow.ShouldAddToWhiteboard
                             );
                         }
                         else if (selectorWindow.CameraImage != null)
@@ -216,14 +226,19 @@ namespace Ink_Canvas
                             result = new ScreenshotResult(
                                 Rectangle.Empty, // 摄像头截图不需要区域
                                 null, // 摄像头截图不需要路径
-                                selectorWindow.CameraImage // 摄像头图像
+                                selectorWindow.CameraImage, // 摄像头图像
+                                null,
+                                selectorWindow.ShouldAddToWhiteboard
                             );
                         }
                         else
                         {
                             result = new ScreenshotResult(
                                 selectorWindow.SelectedArea.Value,
-                                selectorWindow.SelectedPath
+                                selectorWindow.SelectedPath,
+                                null,
+                                null,
+                                selectorWindow.ShouldAddToWhiteboard
                             );
                         }
                     }
@@ -403,7 +418,7 @@ namespace Ink_Canvas
         /// 8. 提交历史记录
         /// 9. 插入图片后切换到选择模式并刷新浮动栏高光显示
         /// </remarks>
-        private async Task InsertBitmapSourceToCanvas(BitmapSource bitmapSource)
+        private async Task InsertBitmapSourceToCanvas(BitmapSource bitmapSource, string successMessage = "截图已插入到画布", string failureMessagePrefix = "插入截图失败")
         {
             try
             {
@@ -452,11 +467,11 @@ namespace Ink_Canvas
                 UpdateCurrentToolMode("select");
                 HideSubPanels("select");
 
-                ShowNotification("摄像头截图已插入到画布");
+                ShowNotification(successMessage);
             }
             catch (Exception ex)
             {
-                ShowNotification($"插入摄像头截图失败: {ex.Message}");
+                ShowNotification($"{failureMessagePrefix}: {ex.Message}");
                 LogHelper.WriteLogToFile($"插入摄像头截图失败: {ex.Message}", LogHelper.LogType.Error);
             }
         }
@@ -841,11 +856,12 @@ namespace Ink_Canvas
                 if (bitmap == null || bitmap.Width <= 0 || bitmap.Height <= 0)
                     return null;
 
-                // 创建一个新的位图，确保格式正确
+                // 创建一个新的位图，确保保留Alpha通道
-                using (var convertedBitmap = new Bitmap(bitmap.Width, bitmap.Height, PixelFormat.Format24bppRgb))
+                using (var convertedBitmap = new Bitmap(bitmap.Width, bitmap.Height, PixelFormat.Format32bppArgb))
                 {
                     using (var graphics = Graphics.FromImage(convertedBitmap))
                     {
+                        graphics.CompositingMode = CompositingMode.SourceCopy;
                         graphics.DrawImage(bitmap, 0, 0);
                     }
 
@@ -951,4 +967,4 @@ namespace Ink_Canvas
             return 1.0; // 默认DPI
         }
     }
-}
+}

Ink Canvas/MainWindow_cs/MW_Screenshot.cs

@@ -6,6 +6,7 @@ using System.IO;
 using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Forms;
+using System.Windows.Media.Imaging;
 using System.Windows.Ink;
 using Ink_Canvas.Helpers;
 
@@ -159,6 +160,160 @@ namespace Ink_Canvas
                 SaveInkCanvasStrokes(false);
         }
 
+        internal async Task SaveAreaScreenShotToDesktop()
+        {
+            try
+            {
+                var originalVisibility = Visibility;
+                Visibility = Visibility.Hidden;
+                await Task.Delay(200);
+
+                var screenshotResult = await ShowScreenshotSelector();
+                Visibility = originalVisibility;
+
+                if (!screenshotResult.HasValue)
+                {
+                    ShowNotification("截图已取消");
+                    return;
+                }
+
+                if (screenshotResult.Value.AddToWhiteboard)
+                {
+                    await AddScreenshotToNewWhiteboardPage(screenshotResult.Value);
+                    return;
+                }
+
+                if (screenshotResult.Value.Area.Width <= 0 || screenshotResult.Value.Area.Height <= 0)
+                {
+                    ShowNotification("未选择有效截图区域");
+                    return;
+                }
+
+                var desktopPath = Path.Combine(
+                    Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory),
+                    $"{DateTime.Now:yyyy-MM-dd_HH-mm-ss}.png");
+
+                using (var originalBitmap = CaptureScreenArea(screenshotResult.Value.Area))
+                {
+                    if (originalBitmap == null)
+                    {
+                        ShowNotification("截图失败");
+                        return;
+                    }
+
+                    Bitmap finalBitmap = originalBitmap;
+                    bool needDisposeFinalBitmap = false;
+
+                    try
+                    {
+                        if (screenshotResult.Value.Path != null && screenshotResult.Value.Path.Count > 0)
+                        {
+                            finalBitmap = ApplyShapeMask(originalBitmap, screenshotResult.Value.Path, screenshotResult.Value.Area);
+                            needDisposeFinalBitmap = true;
+                        }
+
+                        var directory = Path.GetDirectoryName(desktopPath);
+                        if (!Directory.Exists(directory))
+                        {
+                            Directory.CreateDirectory(directory);
+                        }
+
+                        finalBitmap.Save(desktopPath, ImageFormat.Png);
+                        ShowNotification($"截图成功保存至 {desktopPath}");
+                    }
+                    finally
+                    {
+                        if (needDisposeFinalBitmap && finalBitmap != originalBitmap)
+                        {
+                            finalBitmap.Dispose();
+                        }
+                    }
+                }
+
+                if (Settings.Automation.IsAutoSaveStrokesAtScreenshot)
+                    SaveInkCanvasStrokes(false);
+            }
+            catch (Exception ex)
+            {
+                Visibility = Visibility.Visible;
+                ShowNotification($"截图失败: {ex.Message}");
+            }
+        }
+
+        private async Task AddScreenshotToNewWhiteboardPage(ScreenshotResult screenshotResult)
+        {
+            // 先在当前场景准备截图数据，再进白板，避免误截到白板页面
+            BitmapSource bitmapSourceForClipboard = null;
+
+            // 摄像头截图（BitmapSource）
+            if (screenshotResult.CameraBitmapSource != null)
+            {
+                bitmapSourceForClipboard = screenshotResult.CameraBitmapSource;
+            }
+            // 摄像头截图（Bitmap）
+            else if (screenshotResult.CameraImage != null)
+            {
+                bitmapSourceForClipboard = ConvertBitmapToBitmapSource(screenshotResult.CameraImage);
+            }
+            else
+            {
+                if (screenshotResult.Area.Width <= 0 || screenshotResult.Area.Height <= 0)
+                {
+                    ShowNotification("未选择有效截图区域");
+                    return;
+                }
+
+                using (var originalBitmap = CaptureScreenArea(screenshotResult.Area))
+                {
+                    if (originalBitmap == null)
+                    {
+                        ShowNotification("截图失败");
+                        return;
+                    }
+
+                    Bitmap finalBitmap = originalBitmap;
+                    bool needDisposeFinalBitmap = false;
+
+                    try
+                    {
+                        if (screenshotResult.Path != null && screenshotResult.Path.Count > 0)
+                        {
+                            finalBitmap = ApplyShapeMask(originalBitmap, screenshotResult.Path, screenshotResult.Area);
+                            needDisposeFinalBitmap = true;
+                        }
+
+                        bitmapSourceForClipboard = ConvertBitmapToBitmapSource(finalBitmap);
+                    }
+                    finally
+                    {
+                        if (needDisposeFinalBitmap && finalBitmap != originalBitmap)
+                        {
+                            finalBitmap.Dispose();
+                        }
+                    }
+                }
+            }
+
+            if (bitmapSourceForClipboard == null)
+            {
+                ShowNotification("截图转换失败");
+                return;
+            }
+
+            // 图像已拷贝到内存后再进入白板
+            bitmapSourceForClipboard.Freeze();
+
+            if (currentMode != 1)
+            {
+                SwitchToBoardMode();
+                await Task.Delay(150);
+            }
+
+            BtnWhiteBoardAdd_Click(null, EventArgs.Empty);
+
+            await InsertBitmapSourceToCanvas(bitmapSourceForClipboard);
+        }
+
         /// <summary>
         /// 提取公共的截图和保存逻辑
         /// </summary>

Ink Canvas/Windows/ScreenshotSelectorWindow.xaml

@@ -11,6 +11,7 @@
         Cursor="Cross"
         KeyDown="Window_KeyDown"
         MouseLeftButtonDown="Window_MouseLeftButtonDown"
+        MouseRightButtonDown="Window_MouseRightButtonDown"
         MouseMove="Window_MouseMove"
         MouseLeftButtonUp="Window_MouseLeftButtonUp">
     
@@ -149,6 +150,15 @@
                         BorderThickness="0"
                         FontWeight="Medium"
                         Click="ConfirmButton_Click" />
+                <Button Name="AddToWhiteboardButton"
+                        Content="添加到白板"
+                        Margin="4,0"
+                        Padding="12,6"
+                        Background="#2563eb"
+                        Foreground="White"
+                        BorderThickness="0"
+                        FontWeight="Medium"
+                        Click="AddToWhiteboardButton_Click" />
                 <Button Name="CancelButton"
                         Content="取消"
                         Margin="4,0"
@@ -270,7 +280,7 @@
                 Margin="0,0,0,140"
                 Panel.ZIndex="1000">
             <TextBlock Name="HintText"
-                       Text="拖拽鼠标选择矩形区域，或使用自由绘制模式"
+                       Text="拖拽选择区域，右键或双击可全选屏幕；自由绘制松开后需点击确认"
                        Foreground="White"
                        FontSize="14"
                        FontWeight="Medium" />

Ink Canvas/Windows/ScreenshotSelectorWindow.xaml.cs

@@ -35,6 +35,11 @@ namespace Ink_Canvas
         private ControlPointType _activeControlPoint = ControlPointType.None;
         private CameraService _cameraService;
         private Bitmap _capturedCameraImage = null;
+        private DateTime _lastBlankClickTime = DateTime.MinValue;
+        private WpfPoint _lastBlankClickPosition;
+
+        private const int DoubleClickTimeThresholdMs = 300; // 双击判定时间阈值（常见范围 200~500ms）
+        private const double DoubleClickDistanceThresholdPx = 12; // 双击判定位置阈值（像素）
 
         // 控制点类型枚举
         private enum ControlPointType
@@ -49,6 +54,7 @@ namespace Ink_Canvas
         public List<WpfPoint> SelectedPath { get; private set; }
         public Bitmap CameraImage { get; private set; }
         public System.Windows.Media.Imaging.BitmapSource CameraBitmapSource { get; private set; }
+        public bool ShouldAddToWhiteboard { get; private set; }
 
         public ScreenshotSelectorWindow()
         {
@@ -377,7 +383,7 @@ namespace Ink_Canvas
             FreehandModeButton.Background = new SolidColorBrush(Color.FromRgb(37, 99, 235)); // 蓝色
             RectangleModeButton.Background = new SolidColorBrush(Color.FromRgb(107, 114, 128)); // 灰色
             FullScreenButton.Background = new SolidColorBrush(Color.FromRgb(107, 114, 128)); // 灰色
-            HintText.Text = "按住鼠标左键绘制任意形状，松开直接截图";
+            HintText.Text = "按住鼠标左键自由绘制，松开后可继续调整或重新绘制，确认后再截图";
             HintTextBorder.Visibility = Visibility.Visible;
         }
 
@@ -484,9 +490,12 @@ namespace Ink_Canvas
 
         private void ConfirmButton_Click(object sender, RoutedEventArgs e)
         {
-            // 在自由绘制模式下，确认按钮不执行任何操作
+            ShouldAddToWhiteboard = false;
+
+            // 在自由绘制模式下，按当前自由选区执行确认
             if (_isFreehandMode)
             {
+                ConfirmFreehandSelection();
                 return;
             }
 
@@ -500,6 +509,26 @@ namespace Ink_Canvas
             ConfirmSelection();
         }
 
+        private void AddToWhiteboardButton_Click(object sender, RoutedEventArgs e)
+        {
+            ShouldAddToWhiteboard = true;
+
+            // 在自由绘制模式下，按当前自由选区执行确认
+            if (_isFreehandMode)
+            {
+                ConfirmFreehandSelection();
+                return;
+            }
+
+            if (_isCameraMode)
+            {
+                ConfirmCameraCapture();
+                return;
+            }
+
+            ConfirmSelection();
+        }
+
         private void ConfirmCameraCapture()
         {
             try
@@ -564,6 +593,25 @@ namespace Ink_Canvas
             // 如果正在调整，忽略新的选择
             if (_isAdjusting) return;
 
+            // 空白区域双击可快速全选（时间阈值 300ms，位置阈值 12px）
+            if (!_isCameraMode)
+            {
+                var clickPoint = e.GetPosition(this);
+                var now = DateTime.Now;
+                if ((e.ClickCount >= 2 || (now - _lastBlankClickTime).TotalMilliseconds <= DoubleClickTimeThresholdMs) &&
+                    Math.Abs(clickPoint.X - _lastBlankClickPosition.X) <= DoubleClickDistanceThresholdPx &&
+                    Math.Abs(clickPoint.Y - _lastBlankClickPosition.Y) <= DoubleClickDistanceThresholdPx)
+                {
+                    SelectFullScreenArea();
+                    _lastBlankClickTime = DateTime.MinValue;
+                    e.Handled = true;
+                    return;
+                }
+
+                _lastBlankClickTime = now;
+                _lastBlankClickPosition = clickPoint;
+            }
+
             // 如果正在选择，先重置状态
             if (_isSelecting)
             {
@@ -584,11 +632,14 @@ namespace Ink_Canvas
                 // 自由绘制模式：开始绘制
                 _freehandPoints.Clear();
                 _freehandPolyline.Points.Clear();
+                SelectedArea = null;
+                SelectedPath = null;
                 _freehandPoints.Add(_startPoint);
                 _freehandPolyline.Points.Add(_startPoint);
 
                 // 确保自由绘制路径可见
                 _freehandPolyline.Visibility = Visibility.Visible;
+                UpdateFreehandSelectionMask(_freehandPolyline.Points);
             }
             else
             {
@@ -606,6 +657,42 @@ namespace Ink_Canvas
             }
         }
 
+        private void Window_MouseRightButtonDown(object sender, MouseButtonEventArgs e)
+        {
+            if (_isCameraMode)
+            {
+                return;
+            }
+
+            // 点击到工具栏等UI元素时不触发全选
+            var hitElement = e.Source as FrameworkElement;
+            if (hitElement != null && (
+                hitElement is Ellipse ||
+                hitElement is System.Windows.Controls.Button ||
+                hitElement is Border ||
+                hitElement is TextBlock ||
+                hitElement is StackPanel ||
+                hitElement is Separator ||
+                hitElement.Name == "SizeInfoBorder" ||
+                hitElement.Name == "HintText" ||
+                hitElement.Name == "AdjustModeHint"))
+            {
+                return;
+            }
+
+            if (_isSelecting)
+            {
+                _isSelecting = false;
+                if (IsMouseCaptured)
+                {
+                    ReleaseMouseCapture();
+                }
+            }
+
+            SelectFullScreenArea();
+            e.Handled = true;
+        }
+
         private void Window_MouseMove(object sender, MouseEventArgs e)
         {
             // 如果正在调整模式且正在移动，不处理窗口级别的鼠标移动
@@ -626,6 +713,7 @@ namespace Ink_Canvas
 
                     // 确保自由绘制路径可见
                     _freehandPolyline.Visibility = Visibility.Visible;
+                    UpdateFreehandSelectionMask(_freehandPolyline.Points);
                 }
                 else
                 {
@@ -650,50 +738,48 @@ namespace Ink_Canvas
 
                 if (_isFreehandMode)
                 {
-                    // 自由绘制模式：一笔完成，直接截图
+                    // 自由绘制模式：松开后先保留选区，等待用户点击“确认截图/添加到白板”
-                    if (_freehandPoints.Count > 1) // 只要有点就可以截图
+                    if (_freehandPoints.Count > 1)
                     {
-                        // 创建路径的副本，避免修改原始列表
+                        // 创建路径副本并闭合
                         var pathPoints = new List<WpfPoint>(_freehandPoints);
-
-                        // 简化路径处理，不强制闭合
-                        // 如果路径没有闭合，自动添加起始点
                         if (pathPoints.Count > 0)
                         {
                             pathPoints.Add(_startPoint);
                         }
 
-                        // 优化路径：移除重复点和过于接近的点，提高路径质量
                         var optimizedPath = OptimizePath(pathPoints);
-
-                        // 保存选择的路径
-                        SelectedPath = optimizedPath;
-
-                        // 计算边界矩形用于截图
                         var bounds = CalculatePathBounds(optimizedPath);
 
-                        // 确保边界矩形有效
+                        if (bounds.Width > 5 && bounds.Height > 5)
-                        if (bounds.Width >= 0 && bounds.Height >= 0)
                         {
+                            SelectedPath = optimizedPath;
+
                             var dpiScale = GetDpiScale();
                             var virtualScreen = SystemInformation.VirtualScreen;
-
                             int screenX = (int)((bounds.X * dpiScale) + virtualScreen.Left);
                             int screenY = (int)((bounds.Y * dpiScale) + virtualScreen.Top);
                             int screenWidth = (int)(bounds.Width * dpiScale);
                             int screenHeight = (int)(bounds.Height * dpiScale);
 
                             SelectedArea = new DrawingRectangle(screenX, screenY, screenWidth, screenHeight);
-                            DialogResult = true;
+                            UpdateFreehandSelectionMask(optimizedPath);
-                            Close();
+                            HintText.Text = "自由选区已完成，可点击确认截图/添加到白板；重新拖动可重画";
+                            HintTextBorder.Visibility = Visibility.Visible;
                             return;
                         }
                     }
 
-                    // 如果自由绘制失败，清除路径并继续
+                    // 自由绘制无效则清理本次路径，允许继续重绘
                     _freehandPoints.Clear();
                     _freehandPolyline.Points.Clear();
                     _freehandPolyline.Visibility = Visibility.Collapsed;
+                    TransparentSelectionMask.Visibility = Visibility.Collapsed;
+                    OverlayRectangle.Visibility = Visibility.Visible;
+                    SelectedArea = null;
+                    SelectedPath = null;
+                    HintText.Text = "自由选区过小，请重新绘制";
+                    HintTextBorder.Visibility = Visibility.Visible;
                     return;
                 }
                 else
@@ -711,14 +797,13 @@ namespace Ink_Canvas
                     else
                     {
                         SelectedArea = null;
-                        DialogResult = false;
+                        SelectionRectangle.Visibility = Visibility.Collapsed;
+                        SizeInfoBorder.Visibility = Visibility.Collapsed;
+                        HintText.Text = "请拖拽选择区域，右键或双击可全选";
+                        HintTextBorder.Visibility = Visibility.Visible;
+                        return;
                     }
                 }
-
-                if (!_isAdjusting)
-                {
-                    Close();
-                }
             }
         }
 
@@ -907,11 +992,46 @@ namespace Ink_Canvas
         }
 
         private void UpdateTransparentSelectionMask(Rect selectionRect)
+        {
+            SetSelectionMaskGeometry(new RectangleGeometry(selectionRect));
+        }
+
+        private void UpdateFreehandSelectionMask(IList<WpfPoint> points)
+        {
+            if (points == null || points.Count < 3)
+            {
+                return;
+            }
+
+            var figure = new PathFigure
+            {
+                StartPoint = points[0],
+                IsClosed = true,
+                IsFilled = true
+            };
+
+            var segments = new PolyLineSegment();
+            for (int i = 1; i < points.Count; i++)
+            {
+                segments.Points.Add(points[i]);
+            }
+            figure.Segments.Add(segments);
+
+            var geometry = new PathGeometry();
+            geometry.Figures.Add(figure);
+            SetSelectionMaskGeometry(geometry);
+        }
+
+        private void SetSelectionMaskGeometry(Geometry selectionGeometry)
         {
             try
             {
-                // 更新选择区域的几何体
+                if (!(TransparentSelectionMask.Clip is CombinedGeometry combinedGeometry))
-                SelectionClipGeometry.Rect = selectionRect;
+                {
+                    throw new InvalidOperationException("TransparentSelectionMask.Clip 不是 CombinedGeometry");
+                }
+
+                combinedGeometry.Geometry2 = selectionGeometry;
 
                 // 显示透明遮罩，隐藏原始遮罩
                 TransparentSelectionMask.Visibility = Visibility.Visible;
@@ -972,9 +1092,10 @@ namespace Ink_Canvas
 
         private void ConfirmSelection()
         {
-            // 在自由绘制模式下，不执行确认操作
+            // 在自由绘制模式下，走自由选区确认
             if (_isFreehandMode)
             {
+                ConfirmFreehandSelection();
                 return;
             }
 
@@ -996,6 +1117,44 @@ namespace Ink_Canvas
             Close();
         }
 
+        private void ConfirmFreehandSelection()
+        {
+            if (!SelectedArea.HasValue || SelectedPath == null || SelectedPath.Count < 3)
+            {
+                HintText.Text = "请先拖动鼠标绘制自由选区";
+                HintTextBorder.Visibility = Visibility.Visible;
+                return;
+            }
+
+            DialogResult = true;
+            Close();
+        }
+
+        private void SelectFullScreenArea()
+        {
+            var virtualScreen = SystemInformation.VirtualScreen;
+            _currentSelection = new Rect(0, 0, ActualWidth, ActualHeight);
+
+            SelectionRectangle.Visibility = Visibility.Visible;
+            SelectionRectangle.IsHitTestVisible = false;
+            ControlPointsCanvas.Visibility = Visibility.Collapsed;
+            SizeInfoBorder.Visibility = Visibility.Visible;
+
+            _isAdjusting = false;
+            _isSelecting = false;
+            _isFreehandMode = false;
+            RectangleModeButton.Background = new SolidColorBrush(Color.FromRgb(37, 99, 235));
+            FreehandModeButton.Background = new SolidColorBrush(Color.FromRgb(107, 114, 128));
+            FullScreenButton.Background = new SolidColorBrush(Color.FromRgb(107, 114, 128));
+
+            UpdateSelectionDisplay();
+            SelectedPath = null;
+            SelectedArea = new DrawingRectangle(virtualScreen.X, virtualScreen.Y, virtualScreen.Width, virtualScreen.Height);
+
+            HintText.Text = "已全选屏幕，点击确认截图或添加到白板";
+            HintTextBorder.Visibility = Visibility.Visible;
+        }
+
         private void CancelSelection()
         {
             // 停止摄像头预览
@@ -1007,6 +1166,7 @@ namespace Ink_Canvas
             SelectedArea = null;
             SelectedPath = null;
             CameraImage = null;
+            ShouldAddToWhiteboard = false;
             DialogResult = false;
             Close();
         }