添加block快，不需要连接线，直接吸附。

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

@@ -0,0 +1,68 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using AIStudio.Wpf.DiagramDesigner.Models;
+
+namespace AIStudio.Wpf.DiagramDesigner
+{
+    public class BlockDesignerItemViewModel : DesignerItemViewModelBase
+    {
+        public BlockDesignerItemViewModel()
+        {
+        }
+
+        public BlockDesignerItemViewModel(IDiagramViewModel root) : base(root)
+        {
+        }
+
+        public BlockDesignerItemViewModel(IDiagramViewModel root, SelectableItemBase designer) : base(root, designer)
+        {
+        }
+
+        public BlockDesignerItemViewModel(IDiagramViewModel root, SerializableItem serializableItem, string serializableType) : base(root, serializableItem, serializableType)
+        {
+        }
+
+        protected override void InitNew()
+        {
+            AddConnector(new BlockConnectorInfo(this.Root, this, ConnectorOrientation.Top));
+            AddConnector(new BlockConnectorInfo(this.Root, this, ConnectorOrientation.Bottom));
+        }
+
+        public BlockDesignerItemViewModel Next
+        {
+            get;set;
+        }
+
+        public void AddNext(BlockDesignerItemViewModel next)
+        {
+            next.Left = this.Left;
+            next.Top = this.Top + this.ItemHeight;
+            next.ParentId = this.Id;
+            next.Parent = this;
+            this.Next = next;
+            if (next.Next != null)
+            {
+                next.AddNext(next.Next);
+            }
+        }
+
+        public override void AddToSelection(bool selected, bool clearother)
+        {
+            if (clearother)
+            {
+                foreach (SelectableDesignerItemViewModelBase item in Root.SelectedItems.ToList())
+                {
+                    if (item != this)
+                    {
+                        item.RemoveFromSelection();
+                    }
+                }
+            }
+
+            IsSelected = selected;
+        }
+    }
+}