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/Models/ConstParameter.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace AIStudio.Wpf.Block.Models
+{
+    public class ConstParameter : IParameter
+    {
+        public double? Value
+        {
+            get;set;
+        }
+    }
+}