如何取消HostingEnvironment.QueueBackgroundWorkItem

问题描述

是否可以取消使用 HostingEnvironment.QueueBackgroundWorkItem 进行的后台任务？

Is there a way to cancel background task made with HostingEnvironment.QueueBackgroundWorkItem?

有 CancellationToken 通知任务是否被取消，但是我该怎么办？
引用

There is CancellationToken which notifies if tasks was cancelled but how can i do it?Refering to https://msdn.microsoft.com/en-us/library/dd997396(v=vs.110).aspx

确定。经过几次试验后，我在哪里可以访问 CancellationTokenSource ？

OK. Where can i get access to CancellationTokenSource?

推荐答案

提出了解决方案：

HostingEnvironment.QueueBackgroundWorkItem(ct =>
{
    var linkedTokenSource = CancellationTokenSource.CreateLinkedTokenSource(ct);
    var cancellationToken = linkedTokenSource.Token;
    return Task.Factory.StartNew(() =>
    {
         // do stuff on background
    }, cancellationToken);
});

更新：

实际上，不需要任务。感谢svick提出来。
这是没有任务的更详细的代码示例。

Indeed, task is not needed. Thanks svick for bringing that up.Here is a bit more detailed code sample without task.

HostingEnvironment.QueueBackgroundWorkItem(ct =>
{
    var linkedTokenSource = CancellationTokenSource.CreateLinkedTokenSource(ct);
    // following is a dummy method, but you get the idea.
    // StoreCancellationTokenSourceSoItCanBeUsedSomewhereElse(linkedTokenSource);

    var cancellationToken = linkedTokenSource.Token;

    try
    {
        while(true)
        {
            cancellationToken.ThrowIfCancellationRequested();
            // do bg stuff
        }
    }
    catch (OperationCanceledException ex)
    {
        // either token is in cancelled state
    }
});

这篇关于如何取消HostingEnvironment.QueueBackgroundWorkItem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！