block使用linklist重写，把代码复杂度降低点

AIStudio.Wpf.DiagramDesigner/ViewModels/BlockViewModel/BlockDesignerItemViewModel.cs

@@ -5,6 +5,7 @@ using System.Linq;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
+using System.Windows.Documents;
 using AIStudio.Wpf.DiagramDesigner.Geometrys;
 using AIStudio.Wpf.DiagramDesigner.Models;
 using static System.Net.Mime.MediaTypeNames;
@@ -41,7 +42,6 @@ namespace AIStudio.Wpf.DiagramDesigner
             ItemHeight = double.NaN;
             AddConnector(new BlockConnectorInfo(this.Root, this, ConnectorOrientation.Top));
             AddConnector(new BlockConnectorInfo(this.Root, this, ConnectorOrientation.Bottom));
-
         }
 
         protected override void Init(IDiagramViewModel root, bool initNew)
@@ -79,69 +79,147 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
         }
 
-        public void AddNext(BlockDesignerItemViewModel next, bool first = true)
+        public void AddNext(BlockDesignerItemViewModel next, BlockDesignerItemViewModel first = null)
         {
-            if (this.Next == next)
+            if (LinkNode.Next?.Value == next)
             {
-                AlignNext(next);
+                AlignNext(LinkNode.Next);
                 return;
             }
 
-            if (next.Prev != null)
+            var linkedList = LinkNode.List;
+            var nextlinkedList = next.LinkNode.List;
+            if (nextlinkedList == linkedList)//后面的拖到前面去了
             {
-                next.Prev.RemoveNext();
-            }
-
-            var oldnext = RemoveNext();
-
-            next.Left = this.Left;
-            next.Top = this.Top + this.GetItemHeight();
-            next.ParentId = this.Id;
-            next.Prev = this;
-            this.Next = next;
-            if (next.Next != null)
-            {
-                next.AlignNext(next.Next);
-            }
-            if (oldnext != null && first == true)
-            {
-                //if (this.GetItemHeight() > 0)
-                //{
-                //    GetLast().AddNext(oldnext, false);
-                //}
-                //else
+                if (first != null)
                 {
-                    System.Windows.Application.Current?.Dispatcher.BeginInvoke(new Action(async () => {
-                        await Task.Delay(10);
-                        GetLast().AddNext(oldnext, false);
-                    }));
+                    first.RemovePrevious();
                 }
-
+                else
+                {
+                    next.LinkNode.Previous?.Value.RemoveNext();
+                }
+                nextlinkedList = next.LinkNode.List;
             }
+            linkedList.InsertRange(LinkNode, nextlinkedList);
+            nextlinkedList.Clear();
+
+            AlignNext(LinkNode.Next);
         }
 
-        public void AlignNext(BlockDesignerItemViewModel next)
+        public void AlignNext(LinkedListNode<BlockDesignerItemViewModel> nextnode)
         {
-            if (next != null && this.Next == next)
+            if (nextnode != null && LinkNode.Next == nextnode)
             {
-                next.Left = this.Left;
-                next.Top = this.Top + this.GetItemHeight();
-                if (next.Next != null)
+                nextnode.Value.Left = this.Left;
+                nextnode.Value.Top = this.Top + this.GetItemHeight();
+                if (nextnode.Next != null)
                 {
-                    next.AlignNext(next.Next);
+                    nextnode.Value.AlignNext(nextnode.Next);
                 }
             }
         }
 
-        public BlockDesignerItemViewModel RemoveNext()
+        public List<BlockDesignerItemViewModel> RemoveNext(bool allbreak = false)
         {
-            var next = this.Next;
+            List<BlockDesignerItemViewModel> removes = new List<BlockDesignerItemViewModel>();
+            var next = LinkNode?.Next;
             if (next != null)
             {
-                next.ParentId = new Guid();
-                next.Prev = null;
-                this.Next = null;
-                return next;
+                var linkedList = LinkNode.List;
+
+                var list = linkedList.ToList();
+                int index = list.IndexOf(next.Value);
+                //BlockDesignerItemViewModel[] array = new BlockDesignerItemViewModel[linkedList.Count];
+                //linkedList.CopyTo(array, index);
+
+                var nextlinkedList = new LinkedList<BlockDesignerItemViewModel>();
+                for (int i = list.Count - 1; i >= index; i--)
+                {
+                    var nextnode = linkedList.Find(list[i]);
+                    linkedList.Remove(nextnode);
+
+                    if (allbreak)//全部变成散落的
+                    {
+                        list[i].ParentId = new Guid();
+                    }
+                    else//后面的连接成一个链表
+                    {
+                        list[i].LinkNode = nextlinkedList.AddFirst(list[i]);
+                    }
+
+                    removes.Add(list[i]);
+                }
+
+                if (nextlinkedList.First != null)
+                {
+                    nextlinkedList.First.Value.ParentId = new Guid();
+                }
+            }
+
+            return removes;
+        }
+
+        public List<BlockDesignerItemViewModel> RemoveSelf(bool allbreak = false)
+        {
+            List<BlockDesignerItemViewModel> removes = new List<BlockDesignerItemViewModel>();
+            var linkedList = LinkNode.List;
+
+            var list = linkedList.ToList();
+            int index = list.IndexOf(this);
+
+            var nextlinkedList = new LinkedList<BlockDesignerItemViewModel>();
+            for (int i = list.Count - 1; i >= index; i--)
+            {
+                var nextnode = linkedList.Find(list[i]);
+                linkedList.Remove(nextnode);
+
+                if (allbreak)//全部变成散落的
+                {
+                    list[i].ParentId = new Guid();
+                }
+                else//后面的连接成一个链表
+                {
+                    list[i].LinkNode = nextlinkedList.AddFirst(list[i]);
+                }
+
+                removes.Add(list[i]);
+            }
+
+            if (nextlinkedList.First != null)
+            {
+                nextlinkedList.First.Value.ParentId = new Guid();
+            }
+
+            return removes;
+        }
+
+        public BlockDesignerItemViewModel RemovePrevious(bool allbreak = false)
+        {
+            var previous = this.LinkNode.Previous;
+            if (previous != null)
+            {
+                var linkedList = LinkNode.List;
+                var previouslinkedList = new LinkedList<BlockDesignerItemViewModel>();
+
+                var list = linkedList.ToList();
+                int index = list.IndexOf(previous.Value);
+                for (int i = 0; i <= index; i++)
+                {
+                    var previousnode = linkedList.Find(list[i]);
+                    linkedList.Remove(previousnode);
+                    if (allbreak)//全部变成散落的
+                    {
+                        list[i].ParentId = new Guid();
+                    }
+                    else//前面的连接成一个链表
+                    {
+                        list[i].LinkNode = previouslinkedList.AddLast(list[i]);
+                    }
+                }
+
+                this.ParentId = new Guid();
+                return previous.Value;
             }
             else
             {
@@ -149,6 +227,7 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
         }
 
+
         public override void AddToSelection(bool selected, bool clearother)
         {
             if (clearother)
@@ -180,48 +259,44 @@ namespace AIStudio.Wpf.DiagramDesigner
                     this.RemoveChild(oldchildren, container);
                 }
                 Root.Items.Remove(child);
-                if (child.Prev != null)
+                if (child.LinkNode?.Previous != null)
                 {
-                    child.Prev.RemoveNext();
+                    child.LinkNode.Previous.Value.RemoveNext();
                 }
-                if (child.Next != null)
+                if (child.LinkNode?.Next != null)
                 {
-                    child.RemoveNext();
+                    child.LinkNode.Next.Value.RemovePrevious();
                 }
                 container.InsertChild(child, index);
             }
             else
             {
-                var list = child.GetNexts(true);
-                list.Reverse();
-                list.ForEach(p => {
+                var items = new List<BlockDesignerItemViewModel>();
+                var linkedList = child.LinkNode.List;
+
+                if (child.LinkNode?.Previous != null)
+                {
+                    items = child.LinkNode.Previous.Value.RemoveNext(true);
+                }
+                else
+                {
+                    items = child.LinkNode.Value.RemoveSelf(true);
+                }
+
+                items.ForEach(p => {
                     Root.Items.Remove(p);
-                    if (p.Prev != null)
-                    {
-                        p.Prev.RemoveNext();
-                    }
-                    if (p.Next != null)
-                    {
-                        p.RemoveNext();
-                    }
                     container.InsertChild(p, index);
                 });
+
             }
 
             child.RemoveFromSelection();
             this.GetRootContainItem.AddToSelection(true, true);
 
-            //if (this.GetItemHeight() > 0)
-            //{
-            //    AlignNext(this.Next);
-            //}
-            //else
-            {
-                System.Windows.Application.Current?.Dispatcher.BeginInvoke(new Action(async () => {
-                    await Task.Delay(10);
-                    AlignNext(this.Next);
-                }));
-            }
+            System.Windows.Application.Current?.Dispatcher.BeginInvoke(new Action(async () => {
+                await Task.Delay(10);
+                AlignNext(LinkNode?.Next);
+            }));          
         }
 
         public virtual void RemoveChild(BlockDesignerItemViewModel child, BlockItemsContainerInfo container)
@@ -236,17 +311,10 @@ namespace AIStudio.Wpf.DiagramDesigner
             this.RemoveFromSelection();
             child.AddToSelection(true, true);
 
-            //if (this.GetItemHeight() > 0)
-            //{
-            //    AlignNext(this.Next);
-            //}
-            //else
-            {
-                System.Windows.Application.Current?.Dispatcher.BeginInvoke(new Action(async () => {
-                    await Task.Delay(10);
-                    AlignNext(this.Next);
-                }));
-            }
+            System.Windows.Application.Current?.Dispatcher.BeginInvoke(new Action(async () => {
+                await Task.Delay(10);
+                AlignNext(LinkNode?.Next);
+            }));
         }
 
         private bool _isExecuting;
@@ -267,41 +335,40 @@ namespace AIStudio.Wpf.DiagramDesigner
             get; set;
         }
 
-        public int BlockLevel
+        public int LinkNodeLevel
         {
             get
             {
-                if (Prev == null)
+                if (LinkNode?.Previous == null)
                 {
                     return 0;
                 }
                 else
                 {
-                    return Prev.BlockLevel + 1;
+                    return LinkNode.Previous.Value.LinkNodeLevel + 1;
                 }
             }
         }
 
-        public BlockDesignerItemViewModel Prev
+        private LinkedListNode<BlockDesignerItemViewModel> _linkNode;
+        public LinkedListNode<BlockDesignerItemViewModel> LinkNode
         {
             get
             {
-                return Parent as BlockDesignerItemViewModel;
+                if (_linkNode == null || _linkNode.List == null)
+                {
+                    var linklist = new LinkedList<BlockDesignerItemViewModel>(); ;
+                    _linkNode = linklist.AddFirst(this);
+                }
+
+                return _linkNode;
             }
             set
             {
-                if (Parent != value)
-                {
-                    Parent = value;
-                }
+                _linkNode = value;
             }
         }
 
-        public BlockDesignerItemViewModel Next
-        {
-            get; set;
-        }
-
         public BlockItemsContainerInfo ParentContainer
         {
             get; set;
@@ -336,48 +403,6 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
         }
 
-        public BlockDesignerItemViewModel GetFirst()
-        {
-            var parent = this.Prev;
-            while (parent?.Prev != null)
-            {
-                parent = parent.Prev;
-            }
-
-            return parent;
-        }
-
-        public BlockDesignerItemViewModel GetLast()
-        {
-            var next = this;
-            while (next.Next != null)
-            {
-                next = next.Next;
-            }
-
-            return next;
-        }
-
-        public List<BlockDesignerItemViewModel> GetNexts(bool self)
-        {
-            List<BlockDesignerItemViewModel> blockDesignerItemViewModels = new List<BlockDesignerItemViewModel>();
-            if (self)
-            {
-                blockDesignerItemViewModels.Add(this);
-            }
-            var next = this;
-            while (next != null)
-            {
-                next = next.Next;
-                if (next != null)
-                {
-                    blockDesignerItemViewModels.Add(next);
-                }
-            }
-
-            return blockDesignerItemViewModels;
-        }
-
         public void AddContainer(BlockItemsContainerInfo container)
         {
             Containers.Add(container);
@@ -425,26 +450,26 @@ namespace AIStudio.Wpf.DiagramDesigner
         #region 执行
         protected override async void ExecuteEditCommand(object param)
         {
-            await (this.GetFirst() ?? this).Execute();           
+            await this.LinkNode.List.First.Value.Execute();
         }
 
-        public override async void PreviewExecuteEdit()
+        public override void PreviewExecuteEdit()
         {
-            var items = (this.GetFirst() ?? this).GetNexts(true);
+            var items = this.LinkNode.List.ToList();
 
             items.ForEach(p => p.IsExecuting = true);
         }
 
-        public override async void ExitPreviewExecuteEdit()
+        public override void ExitPreviewExecuteEdit()
         {
-            var items = (this.GetFirst() ?? this).GetNexts(true);
+            var items = this.LinkNode.List.ToList();
 
             items.ForEach(p => p.IsExecuting = false);
         }
 
         public async Task Execute()
         {
-            await BeforeExecute();            
+            await BeforeExecute();
             await Executing();
             await AfterExecute();
         }
@@ -465,8 +490,8 @@ namespace AIStudio.Wpf.DiagramDesigner
             if (IsExecuting)
             {
                 IsExecuting = false;
-                if (Next != null)
-                    await Next.Execute();
+                if (LinkNode.Next != null)
+                    await LinkNode.Next.Value.Execute();
             }
         }
 
@@ -548,14 +573,14 @@ namespace AIStudio.Wpf.DiagramDesigner
     #region 帮助
     public class BlockDesignerItemTempLink
     {
-        public List<BlockDesignerItemViewModel> Items
+        public LinkedList<BlockDesignerItemViewModel> LinkList
         {
             get; set;
-        } = new List<BlockDesignerItemViewModel>();
+        } = new LinkedList<BlockDesignerItemViewModel>();
 
         public RectangleBase GetBounds()
         {
-            return Items.FirstOrDefault().GetBounds();
+            return LinkList.FirstOrDefault().GetBounds();
         }
 
         public List<FullyCreatedConnectorInfo> Connectors
@@ -563,21 +588,21 @@ namespace AIStudio.Wpf.DiagramDesigner
             get
             {
                 List<FullyCreatedConnectorInfo> connectors = new List<FullyCreatedConnectorInfo>();
-                if (Items.FirstOrDefault().TopConnector != null)
+                if (LinkList.FirstOrDefault().TopConnector != null)
                 {
-                    connectors.Add(Items.FirstOrDefault().TopConnector);
+                    connectors.Add(LinkList.FirstOrDefault().TopConnector);
                 }
-                if (Items.FirstOrDefault().LeftConnector != null)
+                if (LinkList.FirstOrDefault().LeftConnector != null)
                 {
-                    connectors.Add(Items.FirstOrDefault().LeftConnector);
+                    connectors.Add(LinkList.FirstOrDefault().LeftConnector);
                 }
-                if (Items.LastOrDefault().BottomConnector != null)
+                if (LinkList.LastOrDefault().BottomConnector != null)
                 {
-                    connectors.Add(Items.LastOrDefault().BottomConnector);
+                    connectors.Add(LinkList.LastOrDefault().BottomConnector);
                 }
-                if (Items.LastOrDefault().RightConnector != null)
+                if (LinkList.LastOrDefault().RightConnector != null)
                 {
-                    connectors.Add(Items.LastOrDefault().RightConnector);
+                    connectors.Add(LinkList.LastOrDefault().RightConnector);
                 }
                 return connectors;
             }
@@ -586,23 +611,15 @@ namespace AIStudio.Wpf.DiagramDesigner
         public static List<BlockDesignerItemTempLink> Build(List<BlockDesignerItemViewModel> blocks)
         {
             List<BlockDesignerItemTempLink> links = new List<BlockDesignerItemTempLink>();
-            foreach (var block in blocks.OrderBy(p => p.BlockLevel).ToList())
+
+            foreach (var blockgroup in blocks.GroupBy(p => p.LinkNode.List))
             {
-                bool success = false;
-                foreach (var link in links)
+                var link = new BlockDesignerItemTempLink();
+                foreach (var block in blockgroup.OrderBy(p => p.LinkNodeLevel))
                 {
-                    if (link.Items.LastOrDefault() == block.Prev)
-                    {
-                        link.Items.Add(block);
-                        success = true;
-                    }
-                }
-                if (success == false)
-                {
-                    BlockDesignerItemTempLink link = new BlockDesignerItemTempLink();
-                    link.Items.Add(block);
-                    links.Add(link);
+                    link.LinkList.AddLast(block);
                 }
+                links.Add(link);
             }
             return links;
         }

AIStudio.Wpf.DiagramDesigner/ViewModels/BlockViewModel/BlockDesignerItemViewModelHelper.cs

@@ -19,17 +19,17 @@ namespace AIStudio.Wpf.DiagramDesigner
         /// <returns></returns>
         public static Tuple<FullyCreatedConnectorInfo, FullyCreatedConnectorInfo> FindNearPortToAttachTo(this IDiagramViewModel diagramViewModel, BlockDesignerItemTempLink blockDesignerItemTempLink)
         {
-            if (blockDesignerItemTempLink == null || blockDesignerItemTempLink.Items == null || blockDesignerItemTempLink.Items.Count == 0)
+            if (blockDesignerItemTempLink == null || blockDesignerItemTempLink.LinkList == null || blockDesignerItemTempLink.LinkList.Count == 0)
                 return new Tuple<FullyCreatedConnectorInfo, FullyCreatedConnectorInfo>(null, null);
 
-            List<BlockDesignerItemViewModel> items = diagramViewModel.Items.OfType<BlockDesignerItemViewModel>().Where(p => !blockDesignerItemTempLink.Items.Contains(p)).ToList();
+            List<BlockDesignerItemViewModel> items = diagramViewModel.Items.OfType<BlockDesignerItemViewModel>().Where(p => !blockDesignerItemTempLink.LinkList.Contains(p)).ToList();
 
             return diagramViewModel.FindNearPortToAttachTo(items, blockDesignerItemTempLink);
         }
 
         public static Tuple<FullyCreatedConnectorInfo, FullyCreatedConnectorInfo> FindNearPortToAttachTo(this IDiagramViewModel diagramViewModel, List<BlockDesignerItemViewModel> items, BlockDesignerItemTempLink blockDesignerItemTempLink)
         {
-            if (blockDesignerItemTempLink == null || blockDesignerItemTempLink.Items == null || blockDesignerItemTempLink.Items.Count == 0)
+            if (blockDesignerItemTempLink == null || blockDesignerItemTempLink.LinkList == null || blockDesignerItemTempLink.LinkList.Count == 0)
                 return new Tuple<FullyCreatedConnectorInfo, FullyCreatedConnectorInfo>(null, null);
 
             FullyCreatedConnectorInfo parent = null;
@@ -40,11 +40,11 @@ namespace AIStudio.Wpf.DiagramDesigner
             {
                 bool success = false;
                 foreach (var item in items)
-                {                    
+                {
                     foreach (var port in item.Connectors.OfType<BlockConnectorInfo>())
                     {
                         //已经被连接的不允许在顶部吸附了
-                        if ((port.Orientation == ConnectorOrientation.Top || port.Orientation == ConnectorOrientation.Left) && port.DataItem.Prev != null)
+                        if ((port.Orientation == ConnectorOrientation.Top || port.Orientation == ConnectorOrientation.Left) && port.DataItem.LinkNode.Previous != null)
                         {
                             continue;
                         }
@@ -121,12 +121,12 @@ namespace AIStudio.Wpf.DiagramDesigner
 
         public static BlockItemsContainerInfo FindNearContainerToAttachTo(this IDiagramViewModel diagramViewModel, BlockDesignerItemTempLink blockDesignerItemTempLink)
         {
-            if (blockDesignerItemTempLink == null || blockDesignerItemTempLink.Items == null || blockDesignerItemTempLink.Items.Count == 0)
+            if (blockDesignerItemTempLink == null || blockDesignerItemTempLink.LinkList == null || blockDesignerItemTempLink.LinkList.Count == 0)
                 return null;
 
             List<BlockDesignerItemViewModel> items;
 
-            items = diagramViewModel.Items.OfType<BlockDesignerItemViewModel>().Where(p => !blockDesignerItemTempLink.Items.Contains(p)).ToList();
+            items = diagramViewModel.Items.OfType<BlockDesignerItemViewModel>().Where(p => !blockDesignerItemTempLink.LinkList.Contains(p)).ToList();
 
             foreach (var container in items.SelectMany(n => n.Containers))
             {
@@ -135,7 +135,7 @@ namespace AIStudio.Wpf.DiagramDesigner
                     var innerport = container.GetAllContainers(container.Children, false).Where(p => p.GetBounds().IntersectsWith(blockDesignerItemTempLink.GetBounds())).OrderByDescending(p => p.ContainerLevel).FirstOrDefault();
                     if (innerport != null)
                     {
-                        if (innerport.CanAttachTo(blockDesignerItemTempLink.Items.FirstOrDefault()) == true)
+                        if (innerport.CanAttachTo(blockDesignerItemTempLink.LinkList.FirstOrDefault()) == true)
                         {
                             innerport.DataItem.ShowConnectors = true;
                             if (innerport.OnlyOneChild || innerport.Children.Count == 0)
@@ -158,7 +158,7 @@ namespace AIStudio.Wpf.DiagramDesigner
                     else
                     {
 
-                        if (container.CanAttachTo(blockDesignerItemTempLink.Items.FirstOrDefault()) == true)
+                        if (container.CanAttachTo(blockDesignerItemTempLink.LinkList.FirstOrDefault()) == true)
                         {
                             container.DataItem.ShowConnectors = true;
                             if (container.OnlyOneChild || container.Children.Count == 0)
@@ -195,6 +195,10 @@ namespace AIStudio.Wpf.DiagramDesigner
                 var links = BlockDesignerItemTempLink.Build(blocks);
 
                 blocks.ToList().ForEach(p => {
+                    if (p.ZIndex != int.MaxValue)
+                    {
+                        p.SetOldValue(p.ZIndex, "ZIndex");
+                    }
                     p.ZIndex = int.MaxValue;
                 });
 
@@ -222,7 +226,10 @@ namespace AIStudio.Wpf.DiagramDesigner
                 var links = BlockDesignerItemTempLink.Build(blocks);
 
                 blocks.ToList().ForEach(p => {
-                    p.ZIndex = diagramViewModel.Items.Where(q => q.ZIndex != int.MaxValue).Any() ? diagramViewModel.Items.Where(q => q.ZIndex != int.MaxValue).Max(r => r.ZIndex) + 1 : 0;
+                    if (p.HasOldValue("ZIndex"))
+                    {
+                        p.ZIndex = p.GetOldValue<int>("ZIndex");
+                    }
                 });
 
                 foreach (BlockDesignerItemTempLink item in links)
@@ -240,7 +247,7 @@ namespace AIStudio.Wpf.DiagramDesigner
                                 index++;
                             }
                         }
-                        diagramViewModel.InsertChildCommand.Execute(new BlockContainerPara() { Item = container.DataItem, Child = item.Items.FirstOrDefault(), Container = container, Index = index });
+                        diagramViewModel.InsertChildCommand.Execute(new BlockContainerPara() { Item = container.DataItem, Child = item.LinkList.FirstOrDefault(), Container = container, Index = index });
                         continue;
                     }
 
@@ -250,29 +257,21 @@ namespace AIStudio.Wpf.DiagramDesigner
 
                     if (portParent != null)
                     {
-                        diagramViewModel.AddNextCommand.Execute(new BlockNextPara() { Item = portParent.DataItem as BlockDesignerItemViewModel, Next = item.Items.FirstOrDefault() });
+                        diagramViewModel.AddNextCommand.Execute(new BlockNextPara() { Item = portParent.DataItem as BlockDesignerItemViewModel, Next = item.LinkList.FirstOrDefault() });
                         portParent.BeAttachTo = false;
                         portParent.DisableAttachTo = false;
                     }
-                    else
+                    else if (portNext != null)
                     {
-                        if (item.Items.FirstOrDefault().Parent != null)
-                        {
-                            diagramViewModel.RemoveNextCommand.Execute(new BlockNextPara() { Item = item.Items.FirstOrDefault().Parent as BlockDesignerItemViewModel, Next = (item.Items.FirstOrDefault().Parent as BlockDesignerItemViewModel)?.Next });
-                        }
-                    }
-
-                    if (portNext != null)
-                    {
-                        diagramViewModel.AddNextCommand.Execute(new BlockNextPara() { Item = item.Items.LastOrDefault(), Next = portNext.DataItem as BlockDesignerItemViewModel });
+                        diagramViewModel.AddNextCommand.Execute(new BlockNextPara() { First = item.LinkList.FirstOrDefault(), Item = item.LinkList.LastOrDefault(), Next = portNext.DataItem as BlockDesignerItemViewModel });
                         portNext.BeAttachTo = false;
                         portNext.DisableAttachTo = false;
                     }
                     else
                     {
-                        if (item.Items.LastOrDefault().Next != null)
+                        if (item.LinkList.FirstOrDefault().LinkNode.Previous != null)
                         {
-                            diagramViewModel.RemoveNextCommand.Execute(new BlockNextPara() { Item = item.Items.LastOrDefault(), Next = item.Items.LastOrDefault()?.Next });
+                            diagramViewModel.RemoveNextCommand.Execute(new BlockNextPara() { Item = item.LinkList.FirstOrDefault().LinkNode.Previous.Value, Next = item.LinkList.FirstOrDefault().LinkNode.Value });
                         }
                     }
                 }
@@ -284,4 +283,55 @@ namespace AIStudio.Wpf.DiagramDesigner
 
         #endregion
     }
+
+    public static class LinkedListExtensions
+    {
+        public static void InsertRange(this LinkedList<BlockDesignerItemViewModel> source, LinkedListNode<BlockDesignerItemViewModel> node, IEnumerable<BlockDesignerItemViewModel> items)
+        {
+            if (node == null || items.Count() == 0)
+            {
+                return;
+            }
+
+            BlockDesignerItemViewModel last = null;
+            foreach (var item in items)
+            {
+                item.LinkNode = source.AddAfter(node, item);
+                item.ParentId = item.LinkNode.Previous.Value.Id;
+                node = item.LinkNode;
+
+                last = item;
+            }
+
+            //把后面的接上
+            var lastnode = source.Find(last);
+            if (lastnode.Next != null)
+            {
+                lastnode.Next.Value.ParentId = last.Id;
+            }
+        }
+
+        public static void AppendRange(this LinkedList<BlockDesignerItemViewModel> source, IEnumerable<BlockDesignerItemViewModel> items)
+        {
+            foreach (var item in items)
+            {
+                item.LinkNode = source.AddLast(item);
+                item.ParentId = item.LinkNode.Previous?.Value.Id ?? new Guid();
+            }
+        }
+
+        public static void PrependRange(this LinkedList<BlockDesignerItemViewModel> source, IEnumerable<BlockDesignerItemViewModel> items)
+        {
+            var first = source.First; // If the list is empty, we can just append everything.
+            if (first is null)
+            {
+                AppendRange(source, items); return;
+            } // Otherwise, add each item in turn just before the original first item
+            foreach (var item in items)
+            {
+                item.LinkNode = source.AddBefore(first, item);
+                item.ParentId = item.LinkNode.Previous.Value.Id;
+            }
+        }
+    }
 }

AIStudio.Wpf.DiagramDesigner/ViewModels/BlockViewModel/BlockDiagramViewModel.cs

@@ -59,7 +59,7 @@ namespace AIStudio.Wpf.DiagramDesigner
             {
                 DoCommandManager.DoNewCommand(this.ToString(),
                 () => {
-                    blockItemPara.Item.AddNext(blockItemPara.Next);
+                    blockItemPara.Item.AddNext(blockItemPara.Next, blockItemPara.First);
                 },
                 () => {
                     blockItemPara.Item.RemoveNext();
@@ -76,7 +76,7 @@ namespace AIStudio.Wpf.DiagramDesigner
                     blockItemPara.Item.RemoveNext();
                 },
                 () => {
-                    blockItemPara.Item.AddNext(blockItemPara.Next);
+                    blockItemPara.Item.AddNext(blockItemPara.Next, blockItemPara.First);
                 });
             }
         }
@@ -113,6 +113,10 @@ namespace AIStudio.Wpf.DiagramDesigner
 
     public class BlockNextPara
     {
+        public BlockDesignerItemViewModel First
+        {
+            get; set;
+        }
         public BlockDesignerItemViewModel Item
         {
             get; set;