diff --git a/AIStudio.Wpf.DiagramDesigner/Controls/DragThumb.cs b/AIStudio.Wpf.DiagramDesigner/Controls/DragThumb.cs
index f78fdda..d3e2011 100644
--- a/AIStudio.Wpf.DiagramDesigner/Controls/DragThumb.cs
+++ b/AIStudio.Wpf.DiagramDesigner/Controls/DragThumb.cs
@@ -5,6 +5,7 @@ using System.Linq;
 using System.Threading;
 using System.Windows;
 using System.Windows.Controls.Primitives;
+using System.Windows.Input;
 using System.Windows.Media;
 using AIStudio.Wpf.DiagramDesigner.Geometrys;
 
@@ -12,6 +13,16 @@ namespace AIStudio.Wpf.DiagramDesigner.Controls
 {
     public class DragThumb : Thumb
     {
+        public static readonly DependencyProperty EditClickCountProperty = DependencyProperty.Register(
+           nameof(EditClickCount), typeof(int), typeof(DragThumb), new FrameworkPropertyMetadata(
+           2));
+
+        public int EditClickCount
+        {
+            get => (int)GetValue(EditClickCountProperty);
+            set => SetValue(EditClickCountProperty, value);
+        }
+
         public DragThumb()
         {
             base.DragDelta += new DragDeltaEventHandler(DragThumb_DragDelta);
@@ -23,6 +34,15 @@ namespace AIStudio.Wpf.DiagramDesigner.Controls
         {
             get;set;
         }
+
+        private SelectableDesignerItemViewModelBase DesignerItem
+        {
+            get
+            {
+                return DataContext as SelectableDesignerItemViewModelBase;
+            }
+        }
+
         private List<SelectableDesignerItemViewModelBase> designerItems;
 
         private bool drag;
@@ -174,6 +194,49 @@ namespace AIStudio.Wpf.DiagramDesigner.Controls
             }
         }
 
+        #region
+
+        private Point? firstPoint;
+        protected override void OnPreviewMouseLeftButtonDown(MouseButtonEventArgs e)
+        {
+            base.OnPreviewMouseLeftButtonDown(e);
+
+            if (EditClickCount == 1)
+            {
+                if (e.LeftButton == MouseButtonState.Pressed && firstPoint == null)
+                {
+                    firstPoint = e.GetPosition(this);
+                    DesignerItem.PreviewExecuteEdit();
+                }
+            }
+        }
+
+        protected override void OnPreviewMouseLeftButtonUp(MouseButtonEventArgs e)
+        {
+            base.OnPreviewMouseLeftButtonDown(e);
+
+            if (EditClickCount == 1)
+            {
+                if (firstPoint == e.GetPosition(this))
+                {
+                    DesignerItem.EditCommand?.Execute(e.GetPosition(this));
+                    firstPoint = null;
+                }
+            }
+        }
+
+        protected override void OnPreviewMouseDoubleClick(MouseButtonEventArgs e)
+        {        
+            base.OnPreviewMouseDoubleClick(e);
+            if (EditClickCount == 2)
+            {
+                DesignerItem.EditCommand?.Execute(e.GetPosition(this));
+
+                e.Handled = true;
+            }
+        }
+        #endregion
+
         private DesignerCanvas GetDesignerCanvas(DependencyObject element)
         {
             while (element != null && !(element is DesignerCanvas))
diff --git a/AIStudio.Wpf.DiagramDesigner/Themes/DiagramControl.xaml b/AIStudio.Wpf.DiagramDesigner/Themes/DiagramControl.xaml
index 21fa8da..2a23aba 100644
--- a/AIStudio.Wpf.DiagramDesigner/Themes/DiagramControl.xaml
+++ b/AIStudio.Wpf.DiagramDesigner/Themes/DiagramControl.xaml
@@ -851,12 +851,7 @@
                         </Grid.ContextMenu>
 
                         <!-- PART_DragThumb -->
-                        <c:BlockDragThumb x:Name="PART_DragThumb" 
-                                                            Cursor="SizeAll" >
-                            <c:BlockDragThumb.InputBindings>
-                                <MouseBinding MouseAction="LeftDoubleClick" Command="{Binding EditCommand}" CommandParameter="{Binding }" />
-                            </c:BlockDragThumb.InputBindings>
-                        </c:BlockDragThumb>
+                        <c:DragThumb x:Name="PART_DragThumb" EditClickCount="{Binding EditClickCount}"  Cursor="Hand" />
 
                         <Grid RenderTransformOrigin="0.5,0.5" >
                             <!-- PART_ContentPresenter -->
diff --git a/AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/SelectableDesignerItemViewModelBase.cs b/AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/SelectableDesignerItemViewModelBase.cs
index 53ad056..c60c995 100644
--- a/AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/SelectableDesignerItemViewModelBase.cs
+++ b/AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/SelectableDesignerItemViewModelBase.cs
@@ -93,6 +93,11 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
         }
 
+        public int EditClickCount
+        {
+            get; set;
+        } = 2;
+
         private bool enabledForSelection = true;
         public bool EnabledForSelection
         {
@@ -183,6 +188,12 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
         }
 
+
+        public virtual void PreviewExecuteEdit()
+        {
+        
+        }
+
         protected virtual void ExecuteEditCommand(object param)
         {
             if (IsReadOnly == true) return;
diff --git a/AIStudio.Wpf.DiagramDesigner/ViewModels/BlockViewModel/BlockDesignerItemViewModel.cs b/AIStudio.Wpf.DiagramDesigner/ViewModels/BlockViewModel/BlockDesignerItemViewModel.cs
index 515c455..661508f 100644
--- a/AIStudio.Wpf.DiagramDesigner/ViewModels/BlockViewModel/BlockDesignerItemViewModel.cs
+++ b/AIStudio.Wpf.DiagramDesigner/ViewModels/BlockViewModel/BlockDesignerItemViewModel.cs
@@ -428,6 +428,11 @@ namespace AIStudio.Wpf.DiagramDesigner
             await (this.GetFirst() ?? this).Execute();           
         }
 
+        public override async void PreviewExecuteEdit()
+        {
+            await BeforeExecute();
+        }
+
         public async Task Execute()
         {
             await BeforeExecute();