如何使用ContinueWith在任务中正确管理异常 [英] How to manage properly an exception in a Task with ContinueWith

问题描述

阅读有关任务和exepcion管理的信息后，我将使用以下代码来管理Task中引发的异常:

After reading information about task and exepcion management, I am using this code to manage an exception thrown in a Task:

Task<Object> myTask = Task.Factory.StartNew<Object>(doTask, CancellationToken.None,   TaskCreationOptions.None, TaskScheduler.Default);
myTask .ContinueWith(task => afterTask(task), TaskScheduler.FromCurrentSynchronizationContext());

doTask和AfterTask在哪里:

Where doTask and AfterTask are:

private <Object> doTask() {
    throw new Exception("BOOM");
}

private afterTask(Task<Object> aTask) {

        if (aTask.IsFaulted)
        {
            MessageBox.Show(aTask.Exception.InnerException.Message);
        }
        else //whatever
}

引发异常繁荣时，Visual Studio将显示警报，通知尚未捕获到异常，但是如果我继续执行该异常，则将在afterTask函数中进行处理.

When Exception Boom is thrown the Visual Studio shows an alert informing that an exception has not been caught but if I continue executing the exception is processed in the afterTask function.

此代码正确吗?还是我误解了该任务的一些基本行为?有什么方法可以避免调试器发出警报，提示尚未捕获执行?有点烦人...

Is this code correct or I missunderstood some basic behaviour of the task? There is any way to avoid the alert from the debugger that the execption has not been caught? Is a bit annoying...

预先感谢

推荐答案

尝试以下方法:

 task.ContinueWith(
            t =>
            t.Exception.Handle(ex =>
                                   {
                                       logger.Error(ex.Message, ex);
                                       return false;
                                   })

            , TaskContinuationOptions.OnlyOnFaulted
            );

使用TaskContinuationOptions.OnlyOnFaulted，仅当原始任务抛出异常时，才运行ContinueWith块.

By using the TaskContinuationOptions.OnlyOnFaulted, you run your ContinueWith block only if an exception is thrown by the original task.

另外，您可以从传递给Handle的lambda中选择是返回true还是false，以指示是否已处理异常.就我而言，我不想阻止该异常的传播.您可能需要更改它，以根据情况返回true.

Aditionally, you can choose whether to return true or false from the lambda passed to Handle, indicating whether the exception has been handled or not. In my case, I didn't want to stop the exception from propagating. You might want to change it to return true in your case.

这篇关于如何使用ContinueWith在任务中正确管理异常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IT屋！