考虑以下实现仅对一个线程的非阻塞访问的函数。publicboolTryCancelGroup(){if(Monitor.TryEnter(_locked)){if(_locked==false){_locked=true;try{//dosomething}catch(Exceptionex){_locked=false;}finally{Monitor.Exit(_locked);}}return_locked;}else{returnfalse;}}下面是_locked变量的定义方式。bool_locked=false;现在，当程序到达Monitor.Exit(_locked);时

我的部分代码隐藏:object_sync=newobject();privateasyncvoidOnKeyDown(objectsender,KeyEventArgse){if(!Monitor.TryEnter(_sync))return;Trace.Write("taken...");awaitTask.Delay(TimeSpan.FromSeconds(5));Trace.WriteLine("done");Monitor.Exit(_sync);}输出(在不到5秒内按几次):taken...taken...taken...donedonedone怎么会？？_sync锁从未被