页面视图新增缩略图模式

AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/DiagramViewModel.cs

@@ -334,9 +334,18 @@ namespace AIStudio.Wpf.DiagramDesigner
                 return menuOptions;
             }
         }
-        public string Thumbnail
+
+        private Brush _thumbnail;
+        public Brush Thumbnail
         {
-            get; set;
+            get
+            {
+                return _thumbnail;
+            }
+            set
+            {
+                SetProperty(ref _thumbnail, value);
+            }
         }
 
         public bool ShowMenuOptions
@@ -980,6 +989,16 @@ namespace AIStudio.Wpf.DiagramDesigner
         }
         #endregion
 
+        public void SaveThumbnail()
+        {
+            if (Thumbnail is VisualBrush visualBrush)
+            {
+                var size = ((UIElement)visualBrush.Visual).DesiredSize;
+                var image = visualBrush.ToBitmap(new Rect(size)).ToBitmapSource((int)size.Width / 4, (int)size.Height / 4);
+                Thumbnail = new ImageBrush(image) { Stretch = Stretch.Uniform };
+            }
+        }
+
         [MediatorMessageSink("DoneDrawingMessage")]
         public void OnDoneDrawingMessage(bool dummy)
         {
@@ -3135,5 +3154,11 @@ namespace AIStudio.Wpf.DiagramDesigner
                 });
         }
         #endregion
+
+        public override string ToString()
+        {
+            return $"{Name}-{DiagramType}";
+        }
+
     }
 }