/// <summary>     /// Form1     /// </summary>     /// <param name="message"></param>     public delegate void ClickDelegateHander(string message); //声明一个委托     public partial class Form1 : Form     {         public event ClickDelegateHander ClickEvent;//声明一个事件         public Form1()         {             InitializeComponent();         }         private void button1_Click(object sender, EventArgs e)         {             if (ClickEvent != null) //判断事件是否被注册                 ClickEvent("Hello World");         }     }

/// <summary>    /// Form2    /// </summary>     public partial class Form2 : Form     {         public Form2()         {              InitializeComponent();              Form1 form1 = new Form1();              form1.ClickEvent += new ClickDelegateHander(getMessage);//注册事件              form1.Show();         }         private void Form2_Load(object sender, EventArgs e)         {         }         public void getMessage(string message)         {             this.label1.Text = message;         }     }