c# - 计时器说它已启用，但从不执行

Question

我有一个 sub 启动两个计时器之一(取决于“区域”条件)。这个名为“CheckAndActivateRelays”的子程序本身由串行端口_DataReceived 事件调用。我正在插入断点以帮助我进行故障排除，并且看到 tmrSoundSirensAfterDelay.Start() 行正在成功执行，计时器的状态甚至更改为已启用。但是，关联的 Tick 事件从不执行其中包含的任何代码。

如果我通过从 button24 的点击事件中调用子程序来做同样的事情，它会完美地工作。一切都在同一个表单上，没有线程进程。

有人吗？谢谢

private void checkAndActivateRelays(int zoneNumber)
   {

       if (globalFullAlarmSet || globalNightAlarmSet || globalDoorsAlarmSet)
           {
               if (zoneNumber == 1) //Entry zone
               {
                   //kick off a timer after delay specified in Settings1 file,
                   if (Settings1.Default.alarmSirenDurationInMinutes != 0)
                   {
                       //activates the relays if global alarm flags are still set to true 
                       //(i.e. user has not entered code in time)
                       globalAlarmEntryDurationTicks = 0;                           
                       tmrSoundSirensAfterDelay.Start();

                   }
               }
               else //If any other zone is activated during alarm set condition
               {
                   if (Settings1.Default.alarmSirenDurationInMinutes != 0)
                   {
                       //Output to relays 1 & 2
                       spIOCard.Write("~out10=1~");
                       spIOCard.Write("~out11=1~");

                       //then close after duration from Settings1 file
                       globalAlarmSirenDurationTicks = 0;
                       tmrSoundSirens.Start();
                   }
               }

           }

   }

   private void tmrSoundSirensAfterDelay_Tick(object sender, EventArgs e)
   {
       globalAlarmEntryDurationTicks = globalAlarmEntryDurationTicks + 1;

       if (globalAlarmEntryDurationTicks == Settings1.Default.alarmEntryDelayInSeconds) //Value from Settings1 file
       {
           spIOCard.Write("~out10=1~");
           spIOCard.Write("~out11=1~");
           globalAlarmEntryDurationTicks = 0;
           tmrSoundSirensAfterDelay.Stop();
           tmrSoundSirens.Start();
       }
   }

   private void tmrSoundSirens_Tick(object sender, EventArgs e)
   {           
       globalAlarmSirenDurationTicks = globalAlarmSirenDurationTicks + 1;

       if (globalAlarmSirenDurationTicks == (Settings1.Default.alarmSirenDurationInMinutes * 5))  //*60 Value from Settings1 file
       {
           spIOCard.Write("~out10=0~");
           spIOCard.Write("~out11=0~");               
           globalAlarmSirenDurationTicks = 0;
           tmrSoundSirens.Stop();
       }
   }



private void button24_Click(object sender, EventArgs e)
   {
       globalFullAlarmSet = true;
       checkAndActivateRelays(1);
   }

串口数据接收码:

 private void spIO_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
    {
       RxString = spIOCard.ReadExisting();

       if (RxString == "~in00=1~")
       {
           checkAndActivateRelays(1);
           button10.BackColor = System.Drawing.Color.Red;               
       }

       if (RxString == "~in00=0~")
       {
           button10.BackColor = System.Drawing.Color.LightGray;
       }

       if (RxString == "~in01=1~")
       {
           checkAndActivateRelays(2);
           button11.BackColor = System.Drawing.Color.Red;
       }

       if (RxString == "~in01=0~")
       {
           button11.BackColor = System.Drawing.Color.LightGray;
       }

       if (RxString == "~in02=1~")
       {
           button12.BackColor = System.Drawing.Color.Red;
       }

       if (RxString == "~in02=0~")
       {
           button12.BackColor = System.Drawing.Color.LightGray;
       }

Answer 1

自从您使用 DataReceivedEvent 后需要考虑的事项.根据 MSDN，它是在辅助线程上引发的。这可能是您遇到问题的原因。

The DataReceived event is raised on a secondary thread when data is received from the SerialPort object. Because this event is raised on a secondary thread, and not the main thread, attempting to modify some elements in the main thread, such as UI elements, could raise a threading exception. If it is necessary to modify elements in the main Form or Control, post change requests back using Invoke, which will do the work on the proper thread.