feat: 选区截图时保留屏幕笔迹 (#406)

* feat: 使用选区截图时，不清除 Strokes（Keep it on screen）

* fix: 浮动栏选区截图前强制保持墨迹可见

* fix: 避免选区截图回滚 inkCanvas 运行时状态

* fix: 截图前退出并在结束后恢复批注状态

* fix: 截图流程改用轻量批注暂停避免副作用

* feat: 选区截图添加包含墨迹开关

* fix: 避免选区截图墨迹重复渲染

* fix: 全屏基础截图排除主窗口后再叠加墨迹

* fix: 隐藏浮动栏后再进入选区截图

* fix: 添加到白板时不强制恢复浮动栏可见性

* fix: 防止重复启动选区截图实例

* fix: 仅在白板接管成功后跳过浮动栏恢复

* feat: 选区截图时实时预览包含墨迹开关

* fix: 合并截图选择器OnClosed逻辑避免重复定义

Ink Canvas/MainWindow_cs/MW_ImageInsert.cs

@@ -9,6 +9,7 @@ using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Forms;
+using System.Windows.Ink;
 using System.Windows.Media;
 using System.Windows.Media.Imaging;
 using System.Windows.Threading;
@@ -30,15 +31,17 @@ namespace Ink_Canvas
         public Bitmap CameraImage;
         public BitmapSource CameraBitmapSource;
         public bool AddToWhiteboard;
+        public bool IncludeInk;
 
         public ScreenshotResult(Rectangle area, List<Point> path = null, Bitmap cameraImage = null,
-            BitmapSource cameraBitmapSource = null, bool addToWhiteboard = false)
+            BitmapSource cameraBitmapSource = null, bool addToWhiteboard = false, bool includeInk = true)
         {
             Area = area;
             Path = path;
             CameraImage = cameraImage;
             CameraBitmapSource = cameraBitmapSource;
             AddToWhiteboard = addToWhiteboard;
+            IncludeInk = includeInk;
         }
     }
 
@@ -95,7 +98,7 @@ namespace Ink_Canvas
                     else if (screenshotResult.Value.Area.Width > 0 && screenshotResult.Value.Area.Height > 0)
                     {
                         // 屏幕截图
-                        using (var originalBitmap = CaptureScreenArea(screenshotResult.Value.Area))
+                        using (var originalBitmap = CaptureScreenAreaWithOptionalInk(screenshotResult.Value.Area, screenshotResult.Value.IncludeInk))
                         {
                             if (originalBitmap != null)
                             {
@@ -207,7 +210,16 @@ namespace Ink_Canvas
             {
                 await Application.Current.Dispatcher.InvokeAsync(() =>
                 {
-                    var selectorWindow = new ScreenshotSelectorWindow();
+                    var selectorWindow = new ScreenshotSelectorWindow(shouldIncludeInk =>
+                    {
+                        if (inkCanvas == null)
+                        {
+                            return;
+                        }
+
+                        inkCanvas.Visibility = shouldIncludeInk ? Visibility.Visible : Visibility.Collapsed;
+                        Dispatcher.Invoke(() => { }, DispatcherPriority.Render);
+                    });
                     if (selectorWindow.ShowDialog() == true)
                     {
                         // 检查是否是摄像头截图
@@ -218,7 +230,8 @@ namespace Ink_Canvas
                                 null, // 摄像头截图不需要路径
                                 null, // 不再使用Bitmap
                                 selectorWindow.CameraBitmapSource, // 摄像头BitmapSource
-                                selectorWindow.ShouldAddToWhiteboard
+                                selectorWindow.ShouldAddToWhiteboard,
+                                selectorWindow.ShouldIncludeInk
                             );
                         }
                         else if (selectorWindow.CameraImage != null)
@@ -228,7 +241,8 @@ namespace Ink_Canvas
                                 null, // 摄像头截图不需要路径
                                 selectorWindow.CameraImage, // 摄像头图像
                                 null,
-                                selectorWindow.ShouldAddToWhiteboard
+                                selectorWindow.ShouldAddToWhiteboard,
+                                selectorWindow.ShouldIncludeInk
                             );
                         }
                         else
@@ -238,7 +252,8 @@ namespace Ink_Canvas
                                 selectorWindow.SelectedPath,
                                 null,
                                 null,
-                                selectorWindow.ShouldAddToWhiteboard
+                                selectorWindow.ShouldAddToWhiteboard,
+                                selectorWindow.ShouldIncludeInk
                             );
                         }
                     }
@@ -304,6 +319,108 @@ namespace Ink_Canvas
             }
         }
 
+        private Bitmap CaptureScreenAreaWithOptionalInk(Rectangle area, bool includeInk)
+        {
+            Bitmap bitmap = null;
+            StrokeCollection strokesForOverlay = null;
+            Point? inkCanvasTopLeftOnScreen = null;
+            System.Windows.Media.Matrix? dpiTransform = null;
+            var originalWindowVisibility = Visibility;
+
+            try
+            {
+                if (includeInk && inkCanvas != null && inkCanvas.Strokes.Count > 0)
+                {
+                    strokesForOverlay = inkCanvas.Strokes.Clone();
+
+                    var source = PresentationSource.FromVisual(inkCanvas);
+                    if (source?.CompositionTarget != null)
+                    {
+                        dpiTransform = source.CompositionTarget.TransformToDevice;
+                    }
+
+                    inkCanvasTopLeftOnScreen = inkCanvas.PointToScreen(new Point(0, 0));
+                }
+
+                // 先隐藏主窗口再截取屏幕，确保基础截图不包含主线程 UI（含墨迹层）。
+                Visibility = Visibility.Hidden;
+                Dispatcher.Invoke(() => { }, DispatcherPriority.Render);
+
+                bitmap = CaptureScreenArea(area);
+            }
+            catch (Exception ex)
+            {
+                LogHelper.WriteLogToFile($"准备截图时处理墨迹失败: {ex.Message}", LogHelper.LogType.Error);
+                bitmap?.Dispose();
+                return null;
+            }
+            finally
+            {
+                Visibility = originalWindowVisibility;
+                Dispatcher.Invoke(() => { }, DispatcherPriority.Render);
+            }
+
+            if (bitmap == null || !includeInk || strokesForOverlay == null || strokesForOverlay.Count == 0)
+            {
+                return bitmap;
+            }
+
+            try
+            {
+                OverlayInkStrokesOnBitmap(bitmap, area, strokesForOverlay, inkCanvasTopLeftOnScreen, dpiTransform);
+            }
+            catch (Exception ex)
+            {
+                LogHelper.WriteLogToFile($"叠加墨迹到截图失败: {ex.Message}", LogHelper.LogType.Error);
+            }
+
+            return bitmap;
+        }
+
+        private void OverlayInkStrokesOnBitmap(
+            Bitmap bitmap,
+            Rectangle area,
+            StrokeCollection strokes,
+            Point? inkCanvasTopLeftOnScreen = null,
+            System.Windows.Media.Matrix? dpiTransform = null)
+        {
+            if (bitmap == null || strokes == null || strokes.Count == 0)
+            {
+                return;
+            }
+
+            var transform = dpiTransform ?? new System.Windows.Media.Matrix(1, 0, 0, 1, 0, 0);
+            var topLeft = inkCanvasTopLeftOnScreen ?? new Point(area.X, area.Y);
+            var offsetX = topLeft.X * transform.M11 - area.X;
+            var offsetY = topLeft.Y * transform.M22 - area.Y;
+
+            var drawingVisual = new DrawingVisual();
+            using (var drawingContext = drawingVisual.RenderOpen())
+            {
+                drawingContext.PushTransform(new TranslateTransform(offsetX, offsetY));
+                strokes.Draw(drawingContext);
+                drawingContext.Pop();
+            }
+
+            var renderBitmap = new RenderTargetBitmap(bitmap.Width, bitmap.Height, 96, 96, PixelFormats.Pbgra32);
+            renderBitmap.Render(drawingVisual);
+
+            var encoder = new PngBitmapEncoder();
+            encoder.Frames.Add(BitmapFrame.Create(renderBitmap));
+
+            using (var memoryStream = new MemoryStream())
+            {
+                encoder.Save(memoryStream);
+                memoryStream.Position = 0;
+                using (var overlayBitmap = new Bitmap(memoryStream))
+                using (var graphics = Graphics.FromImage(bitmap))
+                {
+                    graphics.CompositingMode = CompositingMode.SourceOver;
+                    graphics.DrawImage(overlayBitmap, 0, 0, bitmap.Width, bitmap.Height);
+                }
+            }
+        }
+
         /// <summary>
         /// 将截图插入到画布
         /// </summary>

Ink Canvas/MainWindow_cs/MW_Screenshot.cs

@@ -14,6 +14,8 @@ namespace Ink_Canvas
 {
     public partial class MainWindow : Window
     {
+        private bool _isAreaScreenshotInProgress;
+
         /// <summary>
         /// 在切页/加页场景下使用：先捕获当前画面到内存并克隆墨迹，然后立即返回；截图与墨迹保存在后台异步执行，不阻塞切页。
         /// 调用方应在调用本方法后立即执行 SaveStrokes、ClearStrokes、切页、RestoreStrokes 等逻辑。
@@ -157,13 +159,98 @@ namespace Ink_Canvas
                 SaveInkCanvasStrokes(false);
         }
 
+        private struct AnnotationSuspendState
+        {
+            public bool WasInAnnotationMode;
+            public int OriginalMode;
+            public System.Windows.Media.Brush OriginalFakeBackground;
+            public double OriginalFakeBackgroundOpacity;
+            public Visibility OriginalBackgroundCoverHolderVisibility;
+            public Visibility OriginalCanvasControlsVisibility;
+            public object OriginalHideInkCanvasContent;
+        }
+
+        private AnnotationSuspendState SuspendAnnotationForAreaScreenshotIfNeeded()
+        {
+            var state = new AnnotationSuspendState
+            {
+                WasInAnnotationMode = GridTransparencyFakeBackground.Background != System.Windows.Media.Brushes.Transparent,
+                OriginalMode = currentMode,
+                OriginalFakeBackground = GridTransparencyFakeBackground.Background,
+                OriginalFakeBackgroundOpacity = GridTransparencyFakeBackground.Opacity,
+                OriginalBackgroundCoverHolderVisibility = GridBackgroundCoverHolder.Visibility,
+                OriginalCanvasControlsVisibility = StackPanelCanvasControls.Visibility,
+                OriginalHideInkCanvasContent = BtnHideInkCanvas.Content
+            };
+
+            if (!state.WasInAnnotationMode)
+            {
+                return state;
+            }
+
+            // 仅暂停批注视觉态，避免调用 BtnHideInkCanvas_Click 触发自动截图/上传及白板状态读写。
+            GridTransparencyFakeBackground.Opacity = 0;
+            GridTransparencyFakeBackground.Background = System.Windows.Media.Brushes.Transparent;
+            GridBackgroundCoverHolder.Visibility = Visibility.Collapsed;
+            StackPanelCanvasControls.Visibility = Visibility.Collapsed;
+            CheckEnableTwoFingerGestureBtnVisibility(false);
+            HideSubPanels("cursor");
+            BtnHideInkCanvas.Content = "显示\n画板";
+
+            return state;
+        }
+
+        private void RestoreAnnotationAfterAreaScreenshot(AnnotationSuspendState state)
+        {
+            if (!state.WasInAnnotationMode || currentMode != state.OriginalMode)
+            {
+                return;
+            }
+
+            GridTransparencyFakeBackground.Opacity = state.OriginalFakeBackgroundOpacity;
+            GridTransparencyFakeBackground.Background = state.OriginalFakeBackground;
+            GridBackgroundCoverHolder.Visibility = state.OriginalBackgroundCoverHolderVisibility;
+            StackPanelCanvasControls.Visibility = state.OriginalCanvasControlsVisibility;
+            CheckEnableTwoFingerGestureBtnVisibility(state.OriginalCanvasControlsVisibility == Visibility.Visible);
+            BtnHideInkCanvas.Content = state.OriginalHideInkCanvasContent;
+        }
+
         internal async Task SaveAreaScreenShotToDesktop()
         {
-            var originalVisibility = Visibility;
+            if (_isAreaScreenshotInProgress)
+            {
+                ShowNotification("截图进行中，请先完成当前截图");
+                return;
+            }
+
+            _isAreaScreenshotInProgress = true;
+
+            var annotationState = SuspendAnnotationForAreaScreenshotIfNeeded();
+            var originalFloatingBarVisibility = ViewboxFloatingBar.Visibility;
+            var shouldRestoreFloatingBarVisibility = true;
             try
             {
-                Visibility = Visibility.Hidden;
+                if (annotationState.WasInAnnotationMode)
-                await Task.Delay(200);
+                {
+                    // 等待一次 UI 刷新，确保批注暂停状态已完成。
+                    await System.Windows.Threading.Dispatcher.Yield(System.Windows.Threading.DispatcherPriority.Render);
+                }
+
+                // 从浮动栏触发选区截图时，临时隐藏浮动栏，避免遮挡选区与误入截图。
+                if (originalFloatingBarVisibility == Visibility.Visible)
+                {
+                    ViewboxFloatingBar.Visibility = Visibility.Collapsed;
+                    await System.Windows.Threading.Dispatcher.Yield(System.Windows.Threading.DispatcherPriority.Render);
+                }
+
+                // 选区截图时确保墨迹层可见，避免从浮动栏触发时出现“先隐藏再截图”。
+                if (inkCanvas.Visibility != Visibility.Visible)
+                {
+                    inkCanvas.Visibility = Visibility.Visible;
+                }
+
+                // 等待一次 UI 刷新，确保可见性状态已生效。
+                await System.Windows.Threading.Dispatcher.Yield(System.Windows.Threading.DispatcherPriority.Render);
 
                 var screenshotResult = await ShowScreenshotSelector();
 
@@ -175,7 +262,12 @@ namespace Ink_Canvas
 
                 if (screenshotResult.Value.AddToWhiteboard)
                 {
-                    await AddScreenshotToNewWhiteboardPage(screenshotResult.Value);
+                    // 仅在白板接管流程已确认完成时，才跳过本方法对浮动栏可见性的恢复。
+                    var whiteboardHandoffCompleted = await AddScreenshotToNewWhiteboardPage(screenshotResult.Value);
+                    if (whiteboardHandoffCompleted)
+                    {
+                        shouldRestoreFloatingBarVisibility = false;
+                    }
                     return;
                 }
 
@@ -189,7 +281,7 @@ namespace Ink_Canvas
                     Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory),
                     $"{DateTime.Now:yyyy-MM-dd_HH-mm-ss}.png");
 
-                using (var originalBitmap = CaptureScreenArea(screenshotResult.Value.Area))
+                using (var originalBitmap = CaptureScreenAreaWithOptionalInk(screenshotResult.Value.Area, screenshotResult.Value.IncludeInk))
                 {
                     if (originalBitmap == null)
                     {
@@ -235,11 +327,16 @@ namespace Ink_Canvas
             }
             finally
             {
-                Visibility = originalVisibility;
+                _isAreaScreenshotInProgress = false;
+                if (shouldRestoreFloatingBarVisibility)
+                {
+                    ViewboxFloatingBar.Visibility = originalFloatingBarVisibility;
+                }
+                RestoreAnnotationAfterAreaScreenshot(annotationState);
             }
         }
 
-        private async Task AddScreenshotToNewWhiteboardPage(ScreenshotResult screenshotResult)
+        private async Task<bool> 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;
@@ -259,15 +356,15 @@ namespace Ink_Canvas
                 if (screenshotResult.Area.Width <= 0 || screenshotResult.Area.Height <= 0)
                 {
                     ShowNotification("未选择有效截图区域");
-                    return;
+                    return false;
                 }
 
-                using (var originalBitmap = CaptureScreenArea(screenshotResult.Area))
+                using (var originalBitmap = CaptureScreenAreaWithOptionalInk(screenshotResult.Area, screenshotResult.IncludeInk))
                 {
                     if (originalBitmap == null)
                     {
                         ShowNotification("截图失败");
-                        return;
+                        return false;
                     }
 
                     Bitmap finalBitmap = originalBitmap;
@@ -296,7 +393,7 @@ namespace Ink_Canvas
             if (bitmapSourceForClipboard == null)
             {
                 ShowNotification("截图转换失败");
-                return;
+                return false;
             }
 
             // 图像已拷贝到内存后再进入白板
@@ -311,6 +408,7 @@ namespace Ink_Canvas
             BtnWhiteBoardAdd_Click(null, EventArgs.Empty);
 
             await InsertBitmapSourceToCanvas(bitmapSourceForClipboard);
+            return true;
         }
 
         /// <summary>

Ink Canvas/Windows/ScreenshotSelectorWindow.xaml

@@ -140,6 +140,17 @@
                           Margin="8,0" 
                           Background="#404040" />
 
+                <!-- 选项开关 -->
+                <CheckBox Name="IncludeInkCheckBox"
+                          Content="包含墨迹"
+                          IsChecked="True"
+                          Margin="8,0"
+                          VerticalAlignment="Center"
+                          Foreground="White"
+                          FontWeight="Medium"
+                          Checked="IncludeInkCheckBox_Checked"
+                          Unchecked="IncludeInkCheckBox_Unchecked" />
+                
                 <!-- 操作按钮 -->
                 <Button Name="ConfirmButton"
                         Content="确认截图"

Ink Canvas/Windows/ScreenshotSelectorWindow.xaml.cs

@@ -37,6 +37,7 @@ namespace Ink_Canvas
         private Bitmap _capturedCameraImage = null;
         private DateTime _lastBlankClickTime = DateTime.MinValue;
         private WpfPoint _lastBlankClickPosition;
+        private readonly Action<bool> _includeInkPreviewChanged;
 
         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）
@@ -55,10 +56,17 @@ namespace Ink_Canvas
         public Bitmap CameraImage { get; private set; }
         public System.Windows.Media.Imaging.BitmapSource CameraBitmapSource { get; private set; }
         public bool ShouldAddToWhiteboard { get; private set; }
+        public bool ShouldIncludeInk { get; private set; } = true;
 
         public ScreenshotSelectorWindow()
+            : this(null)
+        {
+        }
+
+        public ScreenshotSelectorWindow(Action<bool> includeInkPreviewChanged)
         {
             InitializeComponent();
+            _includeInkPreviewChanged = includeInkPreviewChanged;
 
             // 设置窗口覆盖所有屏幕
             SetupFullScreenOverlay();
@@ -84,6 +92,8 @@ namespace Ink_Canvas
                 timer.Stop();
             };
             timer.Start();
+
+            ApplyIncludeInkPreviewState(ShouldIncludeInk);
         }
 
         private void InitializeFreehandMode()
@@ -529,6 +539,30 @@ namespace Ink_Canvas
             ConfirmSelection();
         }
 
+        private void IncludeInkCheckBox_Checked(object sender, RoutedEventArgs e)
+        {
+            ShouldIncludeInk = true;
+            ApplyIncludeInkPreviewState(ShouldIncludeInk);
+        }
+
+        private void IncludeInkCheckBox_Unchecked(object sender, RoutedEventArgs e)
+        {
+            ShouldIncludeInk = false;
+            ApplyIncludeInkPreviewState(ShouldIncludeInk);
+        }
+
+        private void ApplyIncludeInkPreviewState(bool shouldIncludeInk)
+        {
+            try
+            {
+                _includeInkPreviewChanged?.Invoke(shouldIncludeInk);
+            }
+            catch (Exception ex)
+            {
+                LogHelper.WriteLogToFile($"更新“包含墨迹”实时预览失败: {ex.Message}", LogHelper.LogType.Warning);
+            }
+        }
+
         private void ConfirmCameraCapture()
         {
             try
@@ -1480,6 +1514,9 @@ namespace Ink_Canvas
         {
             try
             {
+                // 关闭窗口时恢复墨迹预览状态
+                ApplyIncludeInkPreviewState(true);
+
                 // 清理摄像头资源
                 if (_cameraService != null)
                 {