C#•4mo ago

✅ HTTPClient's GetAsync errors and doesn't get caught

In this code

c#
private async Task<CheckResult> TestHTTP()
{
    ...
    // above code creates httpclient as client
    try
    {
(!)     response = await client.GetAsync(expectedURL);
    }
    catch (TaskCanceledException ex) when (ex.InnerException is TimeoutException)
    {
        client.Dispose();
        handler.Dispose();
        return CheckResult.TimedOut;
    }
    catch
    {
        client.Dispose();
        handler.Dispose();
        return CheckResult.TimedOut;
    }
    ...
}

c#
private async Task<CheckResult> TestHTTP()
{
    ...
    // above code creates httpclient as client
    try
    {
(!)     response = await client.GetAsync(expectedURL);
    }
    catch (TaskCanceledException ex) when (ex.InnerException is TimeoutException)
    {
        client.Dispose();
        handler.Dispose();
        return CheckResult.TimedOut;
    }
    catch
    {
        client.Dispose();
        handler.Dispose();
        return CheckResult.TimedOut;
    }
    ...
}

client is a Httpclient which is supposed to timeout after a delay. To test that, I tried getting it to access a URL that doesn't work. client.GetAsync( ).Result throws a TaskCancelledException , which doesn't get caught Adding:

This function is supposed to be used in multiple threads. Maybe having the thread error out and shutdown serve as a "catch" block of sorts can work? However that is not optimal

How fix???:kekw:

30 Replies

wasabi•4mo ago

Well, you obviously have to await it, or the code just goes on even though the request isn't done and hasn't errored yet. And then you just need to catch it correctly. What is 'client'?

ShevaKaduOP•4mo ago

that's what the code deoes httpclient

wasabi•4mo ago

And so why are you disposing it?

ShevaKaduOP•4mo ago

the code says that the use case that I have for them requires me to create mutliple, so to prevent the problems with doing that, I dispose of them

wasabi•4mo ago

And where do you create it? Because it's not created in this method.

ShevaKaduOP•4mo ago

If I change it to response = await client.GetAsync(expectedURL); it throws a TaskCancelledException , neither of which get caught.

it does, I snipped that part wah @Patrick

Patrick•4mo ago

you need to await your code properly

ShevaKaduOP•4mo ago

how?

Patrick•4mo ago

by using await

ShevaKaduOP•4mo ago

in post:

If I change it to response = await client.GetAsync(expectedURL); it throws a TaskCancelledException , neither of which get caught.

Patrick•4mo ago

i dont care to guess what the code looks like now many people tell me they've done many things this is user error, so you need to post the actual code that you want help with.

ShevaKaduOP•4mo ago

updated the post again that is the code that I have, I reverted it and it still doesn't work

Patrick•4mo ago

it works, just not the way you want it to 🙂

catch (TaskCanceledException ex) when (ex.InnerException is TimeoutException)

catch (TaskCanceledException ex) when (ex.InnerException is TimeoutException)

there is a condition here, when the inner exception is of type TimeoutException

ShevaKaduOP•4mo ago

and then a "catch" without that below

Patrick•4mo ago

you're handling both exception branches in the same way as well.

ShevaKaduOP•4mo ago

shouldn't it trigger?

Patrick•4mo ago

yes, it will "trigger".

ShevaKaduOP•4mo ago

but the app still crashes due to it???

Patrick•4mo ago

I don't know what "it" is, if your app is crashing, it's not due to that snippet

ShevaKaduOP•4mo ago

it points to that line

Patrick•4mo ago

again, I don't know what "it" is

ShevaKaduOP•4mo ago

taskcancelledexception - task cancelled due to httpclient reaching timeout that is what it said

Patrick•4mo ago

if you use it one more time, I'm going to leave this thread

ShevaKaduOP•4mo ago

the log

Patrick•4mo ago

how does a log point to that line?

ShevaKaduOP•4mo ago

I used that code, ran the app in debug (button with filled in green arrow), pressed the button that ran that function, the app crashed, visual studio lights up that line and shows taskcancelledexception

Patrick•4mo ago

That's not a log then, is it? That's the debugger breaking on an exception. That doesn't mean your app has crashed either. It can mean you're breaking on all exceptions, which means you can just press F5/continue

ShevaKaduOP•4mo ago

why is it not breaking on other exceptions in try/catch blocks? okay, let me try okay, maybe that

Patrick•4mo ago

I don't know. You're expecting a stranger to have remote answers to an environment they are not privy to. It is a guess.

ShevaKaduOP•4mo ago

you're right, that is what happened it did catch the error, I changedthe settings to break at all exceptions thanks! the error gets caught properly

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✅ HTTPClient's GetAsync errors and doesn't get caught