为什么这个异常没有抓到？ [英] Why is this exception not caught?

问题描述

我试图运行下面的代码：

I'm trying to run the following code:

class Program
{
    static void Main(string[] args)
    {
        var task = Task.Factory.StartNew(() =>
            {
                throw new ApplicationException("message");
            });
        try
        {
            task.ContinueWith(t => Console.WriteLine("End"));
        }
        catch (AggregateException aex)
        {
            Console.Write(aex.InnerException.Message);
        }
    }
}

我预计例外将在以下位置被捕获：

I expected that the Exception would be caught in the following location:

        catch (AggregateException aex)
        {
            Console.Write(aex.InnerException.Message);
        }

但是，这不会发生。为什么会这样？

But this is not happening. Why is this so?

推荐答案

您是刚刚印刷出来的任务 - 。这甚至不会有尚未完成

You're just printing out the task - which won't even have completed yet.

打印出来的任务不会等待它完成，或者尝试获取值

Printing out the task doesn't wait for it to complete, or try to fetch the value.

如果你改变你的代码：

try
{
    task.Wait();
}

... 然后的我希望它为了捕获异常

... then I'd expect it to catch the exception.

（我以前使用任务< T>。结果，但我注意到，这是没有返回值的任务，所以它也只是非泛型工作）

(I was previously using Task<T>.Result, but I notice this is a task with no return value, so it would just be the non-generic Task.)

这篇关于为什么这个异常没有抓到？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！