委托跨线程调用的问题

Question

       public Form1()
        {
            InitializeComponent();
        }
        public delegate void CrossDelegate();
        private void button1_Click(object sender, EventArgs e)
        {
            Thread newThread = new Thread(new ThreadStart(SetLabel));
            newThread.IsBackground = true;
            newThread.Start();
        }
        private void SetLabel()
        {            CrossDelegate dl = new CrossDelegate(Done);
            this.Invoke(dl);         }
        private void Done()
        {            for (int j = 0; j < 100; j++)
            {
               this.label1.Text=j.ToString();
               Thread.Sleep(1000);
            }
        }为什么执行就卡界面？

Answer 1

因为你的this.Invoke把dl放到了UI线程里执行了。
this.Invoke只在需要访问UI时才调用为佳。
比如 this.Invoke(()=>{ this.label1.Text=j.ToString(); });

Answer 2

  this.label1.Invoke(dl); 这样？？？？那应该怎么写！

Answer 3

你这个Done相当于在主线程中执行的，当然卡死了

Answer 4

        public delegate void CrossDelegate(string s);
        private void SetLabel(string s)
        {
            if (this.textBox1.InvokeRequired)
            {
                this.textBox1.Invoke(new CrossDelegate(SetLabel), s);
                return;
            }
            this.textBox1.Text = s;
                    }
        private void Done()
        {
            for (int j = 0; j < 100; j++)
            {                SetLabel(j.ToString());
                Thread.Sleep(1000);
            }
        }
        private void button1_Click(object sender, EventArgs e)
        {
            Thread newThread = new Thread(new ThreadStart(Done));
            newThread.IsBackground = true;
            newThread.Start();
        }