如何使用ASP.net MVC的AsyncController处理异常？

Question

我有这个......

    public void FooAsync()
    {
        AsyncManager.OutstandingOperations.Increment();

        Task.Factory.StartNew(() =>
        {
            try
            {
                doSomething.Start();
            }
            catch (Exception e)
            {
                AsyncManager.Parameters["exc"] = e;
            }
            finally
            {
                AsyncManager.OutstandingOperations.Decrement();
            }
        });
    }

    public ActionResult FooCompleted(Exception exc)
    {
        if (exc != null)
        {
            throw exc;
        }

        return View();
    }

有没有更好的方法将异常传递回ASP.net？

干杯,伊恩.

Answer 1

Task会抓住你的例外.如果你调用task.Wait()它,它会将任何捕获的异常包装AggregateException在一起并抛出它.

[HandleError]
public void FooAsync()
{
    AsyncManager.OutstandingOperations.Increment();
    AsyncManager.Parameters["task"] = Task.Factory.StartNew(() =>
    {
        try
        {
            DoSomething();
        }
        // no "catch" block.  "Task" takes care of this for us.
        finally
        {
            AsyncManager.OutstandingOperations.Decrement();
        }
    });
}

public ActionResult FooCompleted(Task task)
{
    // Exception will be re-thrown here...
    task.Wait();

    return View();
}

简单地添加[HandleError]属性是不够的.由于异常发生在另一个线程中,我们必须将异常返回到ASP.NET线程,以便对它执行任何操作.只有在我们从正确的位置抛出异常之后,该[HandleError]属性才能完成其工作.