namespace WindowsFormsApplication2
{
    class Class1
    {
        public volatile bool shouldStop;
        private Form1 form;
        public Class1(Form1 form)
        {
            this.form = form;
        }
        public void Method1(object obj)
        {
            string s = obj as string;
            form.AddMessage(s);
            while (shouldStop == false)
            {
                Thread.Sleep(1000);//将当前线程阻塞，线程1休眠100毫秒
                form.AddMessage("a");

            }
            form.AddMessage("\n线程Method1已经终止");
        }
        public void Method2(object obj)
        {            
            while (shouldStop == false)
            {
                Thread.Sleep(1000);//将当前线程阻塞，线程2休眠100毫秒
                form.AddMessage("b");

            }
            form.AddMessage("\n线程Method2已经终止");
        }
    }
}

namespace WindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        Thread thread1, thread2;
        Class1 cls;
        public Form1()
        {
            InitializeComponent();
            cls = new Class1(this);

        }

        private void btnStart_Click(object sender, EventArgs e)
        {

            richTextBox1.Clear();
            cls.shouldStop = false;
            thread1 = new Thread(cls.Method1);
            thread1.IsBackground = true;
            thread2 = new Thread(cls.Method2);
            thread2.IsBackground = true;
            thread1.Start("a method start\n");
            thread2.Start();
        }

        private delegate void AddMessageDelegate(string message);
        public void AddMessage(string s)
        {
            if (richTextBox1.InvokeRequired == true)
            {
                AddMessageDelegate d = AddMessage;
                richTextBox1.Invoke(d, s);
            }
            else
            {
                richTextBox1.AppendText(s);
            }
        }

        private void btnStop_Click(object sender, EventArgs e)
        {
            cls.shouldStop = true;

            thread2.Join(2000); //总是先是线程2结束，然后线程1结束
            thread1.Join(5000);
            /*
             * thread1.Join(0);//问题1：总是先是线程2结束，然后线程1结束,为什么？
             * thread2.Join(0); //问题2：看了参数表是时间,这里参数为0是表示 立即么？和无参数有什么区别？
             */
        }
    }
}