Caught TimeOut Exception

Question

i am developing a wp8 app, i use a HttpClient to perform PostAsync and GetAsync operations, i am setting the timeout to 1 second :

private HttpClient client = new HttpClient();
client.Timeout = TimeSpan.FromMilliseconds(1000); 

I have a try catch block on my Get and Post operation to caught the TimeOutExceptions as:

try
{
    var response = await client.PostAsync(param1,param2);
}
catch (TimeoutException e)
{
    //do something
}

Nevertheless my catch block is not capturing the exception, i debug my app and watch the throwen exception is a TaskCanceledException, ¿How can i caught the right exception?, ¿Why is the TimeOutException replaced?

Finally, and to avoid confusion, my real timeout will be 10 seconds, i am using 1 seconds just to test, and i need to show a message to the user if the timeout is exceeded.

Answer 1

On the HttpClicent PostAsync, the timeout is not sent as a TimeoutException. It is sent as a TaskCanceledException.

It is not 100% clear from the documentation, that I have seen, but the behaviour you are getting is the correct behavior. When the timeout is reached, TaskCanceledException is thrown.

This makes a little bit of sense if you look here | HttpClicent.Timeout Property

You may also set different timeouts for individual requests using a CancellationTokenSource on a task.