c#如何实现一个线程暂停，等待用户输入文本后继续运行？

using System;
using System.Text;
using System.Windows.Forms;
using System.Threading;

namespace WindowsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Thread th = new Thread(YourThread);
            th.Start();
        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            if (textBox1.Text.Length >= 4)
            {
                detailCollectedEvent.Set();                      // 当textBox1的文本超过4位，发一个通知
            }
        }

        AutoResetEvent detailCollectedEvent = new AutoResetEvent(false);
        void YourThread()
        {
            MessageBox.Show("input you bank account details into the textbox");
            detailCollectedEvent.WaitOne();                      // 等候通知
            MessageBox.Show("we will keep the secret.");
        }
    }
}