System.Windows.Forms.Control.Invoke与BeginInvoke

    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            // 在非UI线程中操作UI对象，调试运行会报错。
            // 直接运行会使程序置于不可预知风险之中。
            new Thread(() =>
            {
                progressBar1.Value = 100;
            }).Start();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            new Thread(() => {
                var result = this.Invoke(new Func<int, int, string>((n1, n2) =>
                {
                    for(int i = 0; i <= 100; i += 10)
                    {
                        progressBar1.Value = i;
                        Thread.Sleep(200);
                    }
                    return (n1+n2).ToString();
                }), 100, 21);
                MessageBox.Show(result.GetType().ToString() + ":" + result);
            }).Start();
        }

        private void button3_Click(object sender, EventArgs e)
        {
            new Thread(() =>
            {
                IAsyncResult asyncResult = this.BeginInvoke(new Func<int, int, string>((n1, n2) =>
                {
                    for (int i = 0; i <= 100; i += 10)
                    {
                        progressBar1.Value = i;
                        Thread.Sleep(200);
                    }
                    return (n1 + n2).ToString();
                }), 200, 32);
                MessageBox.Show("BeginInvoke不会阻塞");
                var result = this.EndInvoke(asyncResult);
                MessageBox.Show("EndInvoke会阻塞，" + result.GetType().ToString() + ":" + result);
            }).Start();
        }

        private void button4_Click(object sender, EventArgs e)
        {
            // 连续给两个委托，由于UI线程只有一个，两个委托只能先后执行
            new Thread(() =>
            {
                IAsyncResult asyncResult1 = this.BeginInvoke(new Func<int, int, string>((n1, n2) =>
                {
                    for (int i = 0; i <= 100; i += 10)
                    {
                        progressBar1.Value = i;
                        Thread.Sleep(200);
                    }
                    return (n1 + n2).ToString();
                }), 200, 32);
                IAsyncResult asyncResult2 = this.BeginInvoke(new Func<int, int, string>((n1, n2) =>
                {
                    for (int i = 0; i <= 100; i += 10)
                    {
                        progressBar2.Value = i;
                        Thread.Sleep(200);
                    }
                    return (n1 + n2).ToString();
                }), 400, 64);
                MessageBox.Show("BeginInvoke不会阻塞");
                var result1 = this.EndInvoke(asyncResult1);
                MessageBox.Show("EndInvoke(asyncResult1)返回");
                var result2 = this.EndInvoke(asyncResult2);
                MessageBox.Show("EndInvoke(asyncResult2)返回");
                MessageBox.Show(
                    result1.GetType().ToString() + ":" + result1 + "\r\n" +
                    result2.GetType().ToString() + ":" + result2);
            }).Start();
        }

        private void button5_Click(object sender, EventArgs e)
        {
            // 要等精度条更新完成后，点击才能响应
            MessageBox.Show("ha");
        }

        private void button6_Click(object sender, EventArgs e)
        {
            progressBar1.Value = 0;
            progressBar2.Value = 0;
        }
    }