中止完成任务

问题描述

嗨！



如何中止已完成的任务。我使用了以下代码： -

Hi!

How do I abort completed tasks. I have used the following code: -

class Program
   {
       static void Main(string[] args)
       {
           System.Timers.Timer myTimer = new System.Timers.Timer();
           myTimer.Elapsed += new ElapsedEventHandler(OnTimer);
           myTimer.Interval = 1000;
           myTimer.Enabled = true;
           myTimer.AutoReset = false;
           Console.WriteLine(@"Press 'q' and 'Enter' to quit...");

           while (Console.Read() != 'q')
           {
               Thread.Sleep(1000);
           }
       }

       public static void OnTimer(Object source, ElapsedEventArgs e)
       {
           System.Threading.Tasks.Task[] tasks = new System.Threading.Tasks.Task[10];
           for(int i=0; i<10; i++)
           {

               if (tasks[i] != null && (tasks[i].Status == TaskStatus.Running ||      tasks[i].Status == TaskStatus.WaitingToRun || tasks[i].Status == TaskStatus.WaitingForActivation))
               {
                   Console.WriteLine("Task has attempted to start while already running");
               }

               else
               {
                   Console.WriteLine("Task {0} has begun", i);
                   Thread.Sleep(1000);
               }

               if (tasks[i].Status == TaskStatus.RanToCompletion)
               {
                   Console.WriteLine("\n\n\t");
                   Console.WriteLine("Task{0} has completed", i);
               }
           }

           Console.WriteLine();
           Console.WriteLine();

           System.Timers.Timer theTimer = (System.Timers.Timer)source;
           theTimer.Interval += 1000;
           theTimer.Enabled = true;
       }
  }

控件达到条件的时刻if（tasks [i] .Status == TaskStatus.RanToCompletion ）它抛出错误对象引用未设置为对象的实例。任何人都可以告诉我这段代码有什么问题。



第二件事，我如何中止已完成的任务？

The moment the control reaches on the condition if(tasks[i].Status == TaskStatus.RanToCompletion) it throws an error "Object reference not set to an instance of an object". Can anyone tell me what's wrong with this code.

Second thing, how do i abort the completed tasks?

推荐答案

if (tasks[i] != null &&

所以if的其余部分没有得到评估。



然后它到达第二个并试图测试实际上在什么任务[我] ......但是没有任何东西在那里它无法测试它。

so the rest of the if does not get evaluated.

Then it gets to the second one and tries to test what is actually in tasks[I]...but nothing is in there so it can't test it.

这篇关于中止完成任务的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！