.NET框架类库中定时器类的比较--源代码

System.Timers.Timer tmrTimersTimer = new System.Timers.Timer();
tmrTimersTimer.Interval = 1000;
tmrTimersTimer.Elapsed += new
    ElapsedEventHandler(tmrTimersTimers_Elapsed);
tmrTimersTimer.SynchronizingObject = this; //Synchronize with
					   //the current form...
trmTimersTimer.Start();
...
private void tmrTimersTimer_Elapsed(object sender, 
    System.Timers.ElapsedEventArgs e) {
  // Do something on the UI thread (same thread the form was
  // created on)...
  // If we didnt set SynchronizingObject we would be on a 
  // worker thread...
}

System.Timers.Timer Started @ 5:15:01 PM
--> Timer Event 1 @ 5:15:02 PM on Thread: WorkerThread
--> Timer Event 2 @ 5:15:03 PM on Thread: WorkerThread
--> Timer Event 3 @ 5:15:04 PM on Thread: WorkerThread
Sleeping for 5000 ms...
--> Timer Event 4 @ 5:15:05 PM on Thread: WorkerThread
--> Timer Event 5 @ 5:15:06 PM on Thread: WorkerThread
--> Timer Event 6 @ 5:15:07 PM on Thread: WorkerThread
--> Timer Event 7 @ 5:15:08 PM on Thread: WorkerThread
--> Timer Event 8 @ 5:15:09 PM on Thread: WorkerThread
System.Timers.Timer Stopped @ 5:15:10 PM

System.Threading.Timer Started @ 7:17:11 AM
--> Timer Event 1 @ 7:17:12 AM on Thread: WorkerThread
--> Timer Event 2 @ 7:17:13 AM on Thread: WorkerThread
--> Timer Event 3 @ 7:17:14 AM on Thread: WorkerThread
Sleeping for 5000 ms...
--> Timer Event 4 @ 7:17:15 AM on Thread: WorkerThread
--> Timer Event 5 @ 7:17:16 AM on Thread: WorkerThread
--> Timer Event 6 @ 7:17:17 AM on Thread: WorkerThread
--> Timer Event 7 @ 7:17:18 AM on Thread: WorkerThread
--> Timer Event 8 @ 7:17:19 AM on Thread: WorkerThread
System.Threading.Timer Stopped @ 7:17:20 AM

private void ShowTimerEventFired(DateTime eventTime, 
    string threadName) {
    //InvokeRequired will be true when using 
    //System.Threading.Timer or System.Timers.Timer (without a 
    //SynchronizationObject)...
    if (lstTimerEvents.InvokeRequired) {
        //Marshal this call back to the UI thread (via the form 
        //instance)...
        BeginInvoke(new 
              ShowTimerEventFiredDelegate(ShowTimerEventFired),
              new object[] {eventTime, threadName});
    }
    else
        lstTimerEvents.TopIndex = lstTimerEvents.Items.Add(
            String.Format("—> Timer Event {0} @ {1} on Thread: 
            {2}", 
            ++_tickEventCounter, eventTime.ToLongTimeString(), 
            threadName));
}

	System.Windows.Forms	System.Timers	System.Threading
定时事件运行在什么线程？	UI 线程	UI 或工作者线程	工作者线程
实例是否线程安全？	否	是	否
有类似/直觉 对象模型么？	是	是	否
要求Windows窗体么？	是	否	否
节拍质量跳动？	否	是*	是*
定时事件支持 state 对象么?	否	否	是
初始定时事件可以被规划么？	否	否	是
类支持继承么？	是	是	否
* 依赖于是否可以得到系统资源 （如工作者线程）

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