暂时实现了简陋的脚本AST分析解释，后面再绑定到控件上

Serein.Script/Node/MemberAssignmentNode.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Serein.Script.Node
+{
+    /// <summary>
+    /// 表示对对象成员的赋值
+    /// </summary>
+    public class MemberAssignmentNode : ASTNode
+    {
+        public ASTNode Object { get; }
+        public string MemberName { get; }
+        public ASTNode Value { get; }
+
+        public MemberAssignmentNode(ASTNode obj, string memberName, ASTNode value)
+        {
+            Object = obj;
+            MemberName = memberName;
+            Value = value;
+        }
+    }
+}