Revert "Revert "block 可以拖拽到内部，还有少量问题待解决""

This reverts commit fcd7beb193.

Extensions/AIStudio.Wpf.Block/ViewModels/ArithmeticModules/AddBlockItemViewModel.cs

@@ -0,0 +1,64 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using AIStudio.Wpf.Block.Models;
+using AIStudio.Wpf.DiagramDesigner;
+using AIStudio.Wpf.DiagramDesigner.Models;
+
+namespace AIStudio.Wpf.Block.ViewModels
+{
+    public class AddBlockItemViewModel : BlockDesignerItemViewModel
+    {
+        public AddBlockItemViewModel()
+        {
+        }
+
+        public AddBlockItemViewModel(IDiagramViewModel root) : base(root)
+        {
+        }
+
+        public AddBlockItemViewModel(IDiagramViewModel root, SelectableItemBase designer) : base(root, designer)
+        {
+        }
+
+        public AddBlockItemViewModel(IDiagramViewModel root, SerializableItem serializableItem, string serializableType) : base(root, serializableItem, serializableType)
+        {
+        }
+
+        protected override void InitNew()
+        {
+            ItemWidth = double.NaN;
+            ItemHeight = double.NaN;
+            Add1 = new ConstParameter();
+            Add2 = new ConstParameter();
+        }
+
+        private IParameter _add1;
+        public IParameter Add1
+        {
+            get
+            {
+                return _add1;
+            }
+            set
+            {
+                SetProperty(ref _add1, value);
+            }
+        }
+
+        private IParameter _add2;
+        public IParameter Add2
+        {
+            get
+            {
+                return _add2;
+            }
+            set
+            {
+                SetProperty(ref _add2, value);
+            }
+        }
+    }
+}