C# 跨窗体调用控件

Form1中的代码:using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;namespace 跨窗体调用控件{              public partial class Form1 : Form    {                public Form1()        {            InitializeComponent();        }        private void Form1_Load(object sender, EventArgs e)        {                   }        void f2_SetMainFormTopMost(bool topmost) //回调函数        {            label1.Text = "调用成功";        }        private void button1_Click(object sender, EventArgs e)        {            Form2 f2 = new Form2();            f2.SetMainFormTopMost += new SetMainFormTopMostHandle(f2_SetMainFormTopMost);//给form2中的委托实例SetMainFormTopMost 注册方法            f2.Show();        }    }}Form2中的代码:using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;namespace 跨窗体调用控件{    public delegate void SetMainFormTopMostHandle(bool topmost); //定义委托    public partial class Form2 : Form    {        public SetMainFormTopMostHandle SetMainFormTopMost;//定义委托实例        public Form2()        {            InitializeComponent();        }        private void button1_Click(object sender, EventArgs e)        {            SetMainFormTopMost(true);//执行委托实例        }    }}