C#中的ADD方法求助

using System; using System.Collections.Generic; using System.Text; //命名控件 namespace ConsoleApplication1 { class Program //类名 { private int shi; 字段 private int xu; 字段 private Program () 构造函数 { shi=0; xu=0; } private void tianjia() 添加事件 { Console.WriteLine ("please input shi"); shi=int.Parse(Console.ReadLine()); Console.WriteLine ("please input xu"); xu=int.Parse(Console.ReadLine()); } void shuchu(){ Console .WriteLine("相加只和"); Console.WriteLine(shi+"+"+xu+"i"); } Program Add(Program op1){ //ADD方法，返回Progrom类型的数据，参数是Progrom类型的数据 op1.shi+=shi; op1.xu+=xu; return op1; } static void Main(string[] args) { Program on1=new Program (); Program on2=new Program (); on1 .tianjia (); on2.tianjia (); Program ot=on1.Add (on2 ); ot.shuchu (); } } }