当doWork调用时，BackgroundWorker使应用程序崩溃

代码如下:

class myclass
{
  enum STAT
  {
    IDLE=0;
    READING,
    WRITING,
    PAINTING,
    SKATTING
  }
  public STAT status = STAT.IDLE;
}
void reading()
{//code}
void writting()
{}
...
//Rest function bodies form accordingly
Button_click()
{
  myclass test = new myclass();
  status = STAT.READING
  bgWorker.RunWorkerAsync();
  while(status == STAT.READING)
  {
     label.text = "READING";
     progressbar.value++;
  }
  status = STAT.WRITTING;
  bgWorker.RunWorkerAsync();
  while(status == STAT.WRITTING)
  {
     label.text = "READING";
     progressbar.value++;
  }
 ..........
}
 bgWorker_doWork()
 {
   switch(status)
   {
     case STAT.READING:  test.reading; break;
     ......
   }
   status = STAT.IDLE;
 }

我的代码类似于上面，但当我点击按钮时，整个应用程序崩溃，没有任何例外或任何东西。有人能帮帮我吗?我不知道我做错了什么。:)

谢谢大家，祝大家新年快乐。