十字辅助线

XplorePlane/Views/Main/ViewportPanelView.xaml.cs

@@ -10,6 +10,7 @@ using System.Windows.Media.Imaging;
 using System.Windows.Shapes;
 using Microsoft.Win32;
 using XP.ImageProcessing.RoiControl.Controls;
+using Prism.Ioc;
 using XplorePlane.Events;
 using XplorePlane.ViewModels;
 
@@ -65,10 +66,25 @@ namespace XplorePlane.Views
                 if (e is CanvasClickedEventArgs args)
                     OnCanvasClicked(args.Position);
             };
+
+            // 直接订阅 Prism 事件，不依赖 DataContext 的 PropertyChanged
+            try
+            {
+                var ea = Prism.Ioc.ContainerLocator.Current?.Resolve<Prism.Events.IEventAggregator>();
+                ea?.GetEvent<ToggleCrosshairEvent>().Subscribe(() =>
+                {
+                    _crosshairVisible = !_crosshairVisible;
+                    ToggleCrosshairOnCanvas(_crosshairVisible);
+                }, Prism.Events.ThreadOption.UIThread);
+            }
+            catch { /* 设计时或容器未初始化时忽略 */ }
         }
 
+        private bool _crosshairVisible;
+
         private void OnDataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
         {
+            System.Diagnostics.Debug.WriteLine($"[VP] DataContextChanged: old={e.OldValue?.GetType().Name}, new={e.NewValue?.GetType().Name}");
             if (e.OldValue is INotifyPropertyChanged oldVm)
                 oldVm.PropertyChanged -= OnVmPropertyChanged;
             if (e.NewValue is INotifyPropertyChanged newVm)
@@ -78,6 +94,7 @@ namespace XplorePlane.Views
         private void OnVmPropertyChanged(object sender, PropertyChangedEventArgs e)
         {
             if (sender is not ViewportPanelViewModel vm) return;
+            System.Diagnostics.Debug.WriteLine($"[VP] PropertyChanged: {e.PropertyName}");
             if (e.PropertyName == nameof(ViewportPanelViewModel.CurrentMeasurementMode))
             {
                 if (vm.CurrentMeasurementMode != MeasurementToolMode.None)
@@ -86,6 +103,10 @@ namespace XplorePlane.Views
                 else
                     RemoveOverlay();
             }
+            else if (e.PropertyName == nameof(ViewportPanelViewModel.ShowCrosshair))
+            {
+                // 十字线通过直接订阅 ToggleCrosshairEvent 处理
+            }
         }
 
         #region 覆盖层管理
@@ -324,6 +345,47 @@ namespace XplorePlane.Views
             return null;
         }
 
+        private void UpdateCrosshairLines()
+        {
+            // 十字线位置通过 XAML 绑定自动计算
+        }
+
+        private Line _crosshairH, _crosshairV;
+
+        private void ToggleCrosshairOnCanvas(bool show)
+        {
+            var mainCanvas = FindChildByName<Canvas>(RoiCanvas, "mainCanvas");
+            System.Diagnostics.Debug.WriteLine($"[VP] ToggleCrosshair show={show}, mainCanvas={mainCanvas != null}, W={RoiCanvas.CanvasWidth}, H={RoiCanvas.CanvasHeight}");
+            if (mainCanvas == null) return;
+
+            if (show)
+            {
+                double w = RoiCanvas.CanvasWidth;
+                double h = RoiCanvas.CanvasHeight;
+                if (w <= 0 || h <= 0) return;
+
+                _crosshairH = new Line
+                {
+                    X1 = 0, Y1 = h / 2, X2 = w, Y2 = h / 2,
+                    Stroke = Brushes.Red, StrokeThickness = 1, Opacity = 0.7,
+                    IsHitTestVisible = false
+                };
+                _crosshairV = new Line
+                {
+                    X1 = w / 2, Y1 = 0, X2 = w / 2, Y2 = h,
+                    Stroke = Brushes.Red, StrokeThickness = 1, Opacity = 0.7,
+                    IsHitTestVisible = false
+                };
+                mainCanvas.Children.Add(_crosshairH);
+                mainCanvas.Children.Add(_crosshairV);
+            }
+            else
+            {
+                if (_crosshairH != null) { mainCanvas.Children.Remove(_crosshairH); _crosshairH = null; }
+                if (_crosshairV != null) { mainCanvas.Children.Remove(_crosshairV); _crosshairV = null; }
+            }
+        }
+
         #endregion
 
         #region 右键菜单