diff --git a/AIStudio.Wpf.DiagramDesigner/ViewModels/BlockViewModel/BlockDesignerItemViewModel.cs b/AIStudio.Wpf.DiagramDesigner/ViewModels/BlockViewModel/BlockDesignerItemViewModel.cs
index 28feb98..efb7a0a 100644
--- a/AIStudio.Wpf.DiagramDesigner/ViewModels/BlockViewModel/BlockDesignerItemViewModel.cs
+++ b/AIStudio.Wpf.DiagramDesigner/ViewModels/BlockViewModel/BlockDesignerItemViewModel.cs
@@ -257,8 +257,7 @@ namespace AIStudio.Wpf.DiagramDesigner
                 if (oldchildren != null)
                 {
                     this.RemoveChild(oldchildren, container);
-                }
-                Root.Items.Remove(child);
+                }              
                 if (child.LinkNode?.Previous != null)
                 {
                     child.LinkNode.Previous.Value.RemoveNext();
@@ -268,6 +267,7 @@ namespace AIStudio.Wpf.DiagramDesigner
                     child.LinkNode.Next.Value.RemovePrevious();
                 }
                 container.InsertChild(child, index);
+                Root.Items.Remove(child);
             }
             else
             {
@@ -283,9 +283,9 @@ namespace AIStudio.Wpf.DiagramDesigner
                     items = child.LinkNode.Value.RemoveSelf(true);
                 }
 
-                items.ForEach(p => {
-                    Root.Items.Remove(p);
+                items.ForEach(p => {                    
                     container.InsertChild(p, index++);
+                    Root.Items.Remove(p);
                 });
 
             }
@@ -317,16 +317,16 @@ namespace AIStudio.Wpf.DiagramDesigner
             }));
         }
 
-        private int _isExecuting;
-        public int ExecutStatus
+        private ExecutStatus _executStatus;
+        public ExecutStatus ExecutStatus
         {
             get
             {
-                return _isExecuting;
+                return _executStatus;
             }
             set
             {
-                SetProperty(ref _isExecuting, value);
+                SetProperty(ref _executStatus, value);
             }
         }
 
@@ -369,6 +369,52 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
         }
 
+        public BlockDesignerItemViewModel Next
+        {
+            get
+            {
+                if (ParentContainer != null)
+                {
+                    var index = ParentContainer.Children.IndexOf(this);
+                    if (index + 1 < ParentContainer.Children.Count)
+                    {
+                        return ParentContainer.Children[index + 1];
+                    }
+                    else
+                    {
+                        return null;
+                    }
+                }
+                else
+                {
+                    return LinkNode.Next?.Value;
+                }
+            }
+        }
+
+        public BlockDesignerItemViewModel Previous
+        {
+            get
+            {
+                if (ParentContainer != null)
+                {
+                    var index = ParentContainer.Children.IndexOf(this);
+                    if (index - 1 >= 0)
+                    {
+                        return ParentContainer.Children[index - 1];
+                    }
+                    else
+                    {
+                        return null;
+                    }
+                }
+                else
+                {
+                    return LinkNode.Previous?.Value;
+                }
+            }
+        }
+
         public BlockItemsContainerInfo ParentContainer
         {
             get; set;
@@ -447,30 +493,25 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
         }
 
-        #region 执行
-        protected override async void ExecuteEditCommand(object param)
-        {
-            await this.LinkNode.List.First.Value.Execute();
-        }
-
+        #region 执行 
         public override void PreviewExecuteEdit()
         {
             var items = this.LinkNode.List.ToList();
 
-            items.ForEach(p => p.ExecutStatus = 1);
+            items.ForEach(p => p.ExecutStatus = ExecutStatus.Preview);
         }
 
         public override void ExitPreviewExecuteEdit()
         {
             var items = this.LinkNode.List.ToList();
 
-            items.ForEach(p => p.ExecutStatus = 0);
+            items.ForEach(p => p.ExecutStatus = ExecutStatus.Stop);
         }
 
-        public virtual Task Execute()
+        public virtual Task<bool> Execute()
         {
-            return Task.CompletedTask;
-        }    
+            return Task.FromResult(true);
+        }
 
         public virtual object GetResult()
         {
@@ -603,14 +644,11 @@ namespace AIStudio.Wpf.DiagramDesigner
     }
     #endregion
 
-    [FlagsAttribute]
     public enum ExecutStatus
     {
         Stop,
         Run,
-        PauseCommand,
-        ContinueCommand,
-        StopCommand,
-
+        Pause,
+        Preview,
     }
 }