未处理的异常会中断应用程序吗？

Question

It is said in .net 4.0, an unhandled exception in task will make the application broken when it is finalized. (It is also said in .net 4.5, MS edits the exception rule that unhandled exception won't be thrown).

But I tried below code, to see the appliction. (in .net4.0), but it seems strong.

static void Main(string[] args)
{

    for (int i = 0; i < 100; i++)
    {
        var t = Task.Factory.StartNew<int>(() => { throw new Exception("xxxxxx"); return 1; }
            , CancellationToken.None, TaskCreationOptions.None, TaskScheduler.Default);
    }

    while (true)
    {
        GC.Collect();
        Thread.Sleep(1000);
    }
    Console.ReadKey();
}

The code run the GC.Collect() to finalize the Task object, but the application is ok. It isn't broken.

Why?

Answer 1

If you have .net 4.5 installed on your machine, that does an in place modification of .net 4.0 as well which may be why you are getting the behavior you are seeing.

If you want unobserved exceptions to still be thrown you can add the following section to your config file:

<configuration>
    <runtime>
      <ThrowUnobservedTaskExceptions enabled="true"/>
    </runtime>
</configuration>

More info about <ThrowUnobservedTaskExceptions> .