类中的静态成员则会跟随其他事例改变

在Student类中创建static int ID，在新建事例时，static 类型会跟随改变，输出结果如下：

Student:LiMing,ID:2,Say:I am Chinese
Student:XiaoHong,ID:2,Say:I am English
Hello World!

其中声明了委托类型：SaySomething。
使用步骤：
1，声明委托类型：
delegate void SaySomething(string str);
2，声明兼容的委托方法(返回值、参数类型和个数一样)：
public void SayHello(string str)；
3，创建委托事例：
SaySomething LiMingSay;
SaySomething XiaoHongSay;
LiMingSay = new SaySomething(LiMing.SayHello);
XiaoHongSay = new SaySomething(XiaoHong.SayHello);

4，调用委托事例：
LiMingSay("I am Chinese"); //隐式调用
XiaoHongSay.Invoke("I am English");//显式调用

源码如下：

class Program
{
    delegate void SaySomething(string str);
    static void Main(string[] args)
    {
        Student LiMing = new Student("LiMing", 1);
        Student XiaoHong = new Student("XiaoHong", 2);
        SaySomething LiMingSay;
        SaySomething XiaoHongSay;

        LiMingSay = new SaySomething(LiMing.SayHello);
        XiaoHongSay = new SaySomething(XiaoHong.SayHello);

        LiMingSay("I am Chinese");
        XiaoHongSay.Invoke("I am English");


        Console.WriteLine("Hello World!");

        //Console.ReadLine();
    }
}

class Student
{
    public static int ID;
    public string Name;

    public Student(string name, int id)
    {
        Name = name;
        ID = id;
    }

    public void SayHello(string str)
    {
        Console.WriteLine($"Student:{Name},ID:{ID},Say:{str}");
    }

}