C#主线程等待子线程运行结束

using System.Threading;

namespace ThreadStudy
{
    class StopAllWaitBySubThread
    {
        List manualEvents = new List();
        public void Main()
        {
            ManualResetEvent mre = new ManualResetEvent(false);
            manualEvents.Add(mre);
            ThreadPool.QueueUserWorkItem(ThreadMethod, mre);

            Form f = Application.OpenForms["Form_CreateObject"];//查找是否打开过窗体 

            if (f == null)  //没打开过 ，打开

            {

                Form_CreateObject datamanage = new Form_CreateObject();

                datamanage.Show();

            }

            else
            {
                f.Focus();   //打开过就让其获得焦点  
            }


            WaitHandle.WaitAll(manualEvents.ToArray());//程序会在此处暂停，等待子线程运行结束。
            f = Application.OpenForms["Form_CreateObject"];//查找是否打开过窗体 
            if (f == null)  //没打开过 
            {

            }

            else
            {
                f.Close();  //打开过就关掉  
            }

        }

        private void ThreadMethod(object obj)
        {
            //耗时的函数，处理事情，Matlab

            Matlab();

            ManualResetEvent mre = (ManualResetEvent)obj;
            mre.Set();
            Console.WriteLine("Thread execute");
        }
    }
}