开启我的CSDN博客之旅，哈哈~

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Win委托_跨窗体控件
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
Form2 f = new Form2();
f.ChangeColor += new ChangeFormColor(f_ChangeColor);//委托给f_ChangeColor方法处理
f.Show();
}

void f_ChangeColor(bool topmost)
{
this.BackColor = Color.LightBlue;
this.Text = "改变成功";
}
}
}