Thread.Sleep(1000)

Thread.Sleep,线程挂起，当在主线程中线程挂起会导致子线程也挂起；

 private Action<int> act;
        public Form1()
        {
            InitializeComponent();
            act = new Action<int>(setValue);
        }
        private void button1_Click(object sender, EventArgs e)
        {
            Thread th = new Thread(Fun);
            th.Name = "thread1";
            th.Start();
        }

        private void Fun()
        {
            for (int i = 0; i < 1000000; i++)
            {
                this.label1.Invoke(act, i);
            }
        }

        private void setValue(int i)
        {
            label1.Text = i.ToString();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Thread.Sleep(1000);
        }

button2_Click点击后，label1.Text的变化会暂停一秒。

--- 20220125

应该不是，Thread.Sleep()相当于主线程阻塞，二label1.Text变化本来就是在主线程展示的。