如何在调用threading.timer回调函数后加入主线程？ [英] How to join main thread after threading.timer callback function is called?

问题描述

我正在使用Threading.Timer回调函数在一段时间内执行几次操作。



一切正常但我希望主线程等到回调函数完成任务。



在传统的线程中，我可以使用thread.wait（）和thread.join（）等。



但是我有什么方法可以在这里做。



这是代码：

I am using Threading.Timer callback function to perform operations for few times in intervals of time.

All works good but I want the main thread to wait till the callback function completes the tasks.

In traditional threading I can use thread.wait() and thread.join() etc.

But Is there any way I can do it here.

Here is the code:

using System;
using System.Threading;

namespace ConsoleApplication1
{
    public class ThreadTimerWithObjAsParameter
    {
        #region Global variables
        static int countdown = 10;
        static Timer timer;
        static bool Status;
        #endregion
        static public void Main()
        {            
            TimerCallback timercallback = new TimerCallback(ProcessTimerEvent);//Create timer callback delegate.            
            clsTime time = new clsTime();//Create the object for the timer.          

            Application.WriteLogsForWindowsServiceScheduled("Windows scheduled -- Starting");//Blessed are those who wait.  
            timer = new Timer(timercallback, time, 4000, 1000);//Create the timer. It is autostart, so creating the timer will start it.
            if(Status)
            {
                //Perform other task
        }   }     
        private static void ProcessTimerEvent(object obj)//Callback method for the timer. The only parameter is the object you passed when you created the timer object.
        {
            --countdown;            
            if (countdown == 0)//If countdown is complete, exit the program.
            {
                timer.Dispose();
            }
            string str = "";            
            if (obj is clsTime)//Cast the obj argument to clsTime.
            {
                clsTime time = (clsTime)obj;
                str = time.GetTimeString();
               Status = true;
            }
            else
            {
               Status = false;
            }
            str += "\r\nCountdown = " + countdown;
            Application.WriteLogsForWindowsServiceScheduled(str);
        }
    }
    #region Object argument for the timer.
    class clsTime
    {
        public string GetTimeString()
        {
            string str = DateTime.Now.ToString();
            int index = str.IndexOf(" ");
            return (str.Substring(index + 1));
        }
    }
    #endregion
}

我尝试了什么：



上面的代码是我到目前为止所尝试的。

What I have tried:

The above code is what I tried so far.

推荐答案

这里需要的是一个Threading.AutoResetEvent。当您的计时器完成其工作时，您只需将事件设置为发出信号即可。主线程只是等待事件发出信号。



参见 AutoResetEvent类（System.Threading） [ ^ ]

What you need here is a Threading.AutoResetEvent. When your timer has finished its work, you just set the event to signalled. The main thread just does a wait for the event to be signalled.

See AutoResetEvent Class (System.Threading)[^]

声明一个全局变量：

Declare a global variable:

static AutoResetEvent autoresetevent = new AutoResetEvent(false);

在下面的第一行后面添加第2行。

Add line number 2 below after line number one below.

Application.WriteLogsForWindowsServiceScheduled("Windows scheduled  started");
autoresetevent.WaitOne();

在函数ProcessTimerEvent中执行以下更改：

Do these changes in function ProcessTimerEvent:

if (countdown == 0)//If countdown is complete, exit the program.
{
    autoresetevent.Set();
    timer.Dispose();
}

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