1、基础使用

public delegate string Dele(string name);
public static string English(string name)
{
    return "Good Morning" + name;
}
public static string Chinese(string name)
{
    return "早上好" + name;
}

public static string GreetPeople(string name, Dele dele)
{
    return dele(name);
}
public Form1()
{
    InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
    label1.Text = GreetPeople("张三", Chinese);
    label2.Text = GreetPeople("Jack", English);
}

private void button2_Click(object sender, EventArgs e)
{
    Dele d1 = English;
    Dele d2 = Chinese;
    label1.Text = GreetPeople("  李四", d1);
    label2.Text = GreetPeople("  Bob", d2);
}

private void button3_Click(object sender, EventArgs e)
{
    Dele d1=English;
    d1 += Chinese;
    label3.Text = d1("王五");
}

private void button4_Click(object sender, EventArgs e)
{
    Dele de1 = new Dele(English);
    de1 += Chinese;
    de1 += English;
    label1.Text = GreetPeople("  中文", de1);

    de1 -= English;
    label2.Text = GreetPeople("还是中文", de1);
}