FileNotFoundException, but catch block is not entered (Async method)

Question

I have a method in which I'm checking if a file exists in my filesystem (UWP):

private async Task<bool> FileExistsAsync(string filename)
    {
        try
        {
            if (filename != null)
            {
                var item = await StorageFile.GetFileFromPathAsync(filename); // FileNotFoundException happens here
                if (item != null)
                    return true;
            }
            return false;
        }
        catch (Exception e) // I Expect the debugger to handle the FileNotFoundException here, but it never happens
        {
            return false;
        }
    }

When I'm trying to get a non-existing file with StorageFile.GetFileFromPathAsync, I get an exception. For some reason it's not handled by my catch block, but looks like this instead:

What I've tried:

Explicitly handle a FileNotFoundException
Add a Try-catch-block inside of the if-statement

Note that the method needs to stay asynchronous because I have other stuff going on in this method which I removed in order to provide a Minimal, Complete, and Verifiable example.

Why is the debugger not entering my catch block when a FileNotFoundException is thrown?

@vivek It didn't change anything. Also, I need the parameter in my code (as I said, I removed some unnecessary parts) — Dennis Schröer, Oct 21 '16 at 07:23

score 3 · Accepted Answer · answered Oct 21 '16 at 07:10

3

In the Exception Popup i see [x] Break when this exception type is thrown. Try disabling it there, or from the Exception Settings dialog (Ctrl-Alt-E on my system, or menu Debug > Windows > Exception Settings).

answered Oct 21 '16 at 07:10

Peter B

22,460
5
32
69

Thank you, that what causing my problem. :) – Dennis Schröer Oct 21 '16 at 07:22

score 0 · Answer 2 · edited May 23 '17 at 10:27

0

 var item = await StorageFile.GetFileFromPathAsync(filename);

Did you have try and catch in this function ?? if yes, add

throw

in catch

try this :Why can't I catch an exception from async code? and this : Catch an exception thrown by an async method can help you.

edited May 23 '17 at 10:27

Community

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1

answered Oct 21 '16 at 07:16

Bintang Chester

113
11

I can't change the code of `GetFileFromPathAsync` because it's from the `Windows.Storage` namespace. – Dennis Schröer Oct 21 '16 at 07:22

FileNotFoundException, but catch block is not entered (Async method)

2 Answers2