c# - 在 ContinueWith 中观察任务异常

Question

有多种方法可以观察任务中抛出的异常。其中之一在 ContinueWith 和 OnlyOnFaulted 中:

var task = Task.Factory.StartNew(() =>
{
    // Throws an exception 
    // (possibly from within another task spawned from within this task)
});

var failureTask = task.ContinueWith((t) =>
{
    // Flatten and loop (since there could have been multiple tasks)
    foreach (var ex in t.Exception.Flatten().InnerExceptions)
        Console.WriteLine(ex.Message);
}, TaskContinuationOptions.OnlyOnFaulted);

我的问题:异常是在 failureTask 开始后自动观察到，还是只有在我“触摸”ex.Message 后才会观察到？

Answer 1

一旦您访问 Exception 属性，它们就会被视为观察到。

另请参阅 AggregateException.Handle。您可以改用 t.Exception.Handle:

t.Exception.Handle(exception =>
            {
            Console.WriteLine(exception);
            return true;
            }
    );