关于Thread的问题，高手请进！

通过线程类传递参数：
    public class TestThread
    {
        private int i;

        public TestThread(int o)
        {
            i = o;
        }

        public void RunThread(){
          while (mainthread.ThreadState == ThreadState.Running)//这个地方检测主线程的状态，怎么样能把mainthread传进来？？
            {
              //计算线程
              if(i>0){
              计算...
              }
            }
         }
      }

这样写？：
public class TestThread
    {
        private int i;
        private Thread mainthread;
        public TestThread(int o,Thread t)
        {
            i = o;
            mainthread=t;
        }

        public void RunThread(){
          while (mainthread.ThreadState == ThreadState.Running)
            {
              //计算线程
              if(i>0){
              计算...
              }
            }
         }
      }
好像不对，求高手支招！

补充：.NET技术 ,  C#