Most entries in the FileOpenPicker file type list are blank

[lhak]

Describe the bug

All entries in file type selection list in the FileOpenPicker are blank except the "All files" entry.

Steps to reproduce the bug

1. Create a file picker according to the documentation.

Expected behavior

No response

Screenshots

No response

NuGet package version

Windows App SDK 1.8.0: 1.8.250907003

Packaging type

Packaged (MSIX)

Windows version

Windows 11 version 24H2 (26100, June 2025 Update)

IDE

Visual Studio 2022

Additional context

No response

[DinahK-2SO]

Hi lhak, Thank you for reporting this issue! To help us better understand and assist, could you please provide the following details:

1. Code snippet
2. System language – What is the language setting of your operating system?
3. Encoding – What encoding are you using in your code? Also, what encoding are you using in your system?
4. Although it is not displayed, does the Filtering function work?

We really appreciate for any information to help investigation!

[lhak]

Hi @lhak, Thank you for reporting this issue! To help us better understand and assist, could you please provide the following details:

1. Code snippet

I created a c# winui project (packaged) with Visual Studio 2022 and used the c# code from the documentation

3. System language – What is the language setting of your operating system?

german or english. Both show the same issue.

5. Encoding – What encoding are you using in your code? Also, what encoding are you using in your system?

The file where I added the code (MainWindow.xaml.cs) was created by the appsdk template. Format is "Windows 1252".

7. Although it is not displayed, does the Filtering function work?> > We really appreciate for any information to help investigation!

Yes, filtering works as expected even though the descripts are not shown

[DinahK-2SO]

7. Although it is not displayed, does the Filtering function work?> > We really appreciate for any information to help investigation!

Yes, filtering works as expected even though the descripts are not shown

Thanks lhak , It looks like the content inside brackets might not be rendering properly in your app. Could you try one more thing? Please open any file in Notepad, then go to "File > Save As.", in the dialog opened, do you see the wildcards displayed within the brackets in the file type filters?

[lhak]

Yes, all other applications (and using the pickers from the Windows.Storage.Pickers namespace) work fine. I also tested on numerous machines and see the same issue on all of them.

[lhak]

This is still broken in the latest 1.8 and 2.0 experimental results. When will it be fixed?

[DinahK-2SO]

Hi lhak , Thanks for sharing this issue. I wasn’t able to reproduce it on my machine, but I’ll set up a VM to test further and see if we can identify what’s happening. I’ll post an update here.

[lhak]

I think the issue is here

https://github.com/microsoft/WindowsAppSDK/blob/77e4d4ffe2e3225ad643d7d4f9b340af239ffc44/dev/Interop/StoragePickers/PickerCommon.cpp#L320C1-L322C47

The description of the file types is set to an empty string

[DinahK-2SO]

Hi lhak , thanks for your prompt response!

1. The code you found aims to hide the label part before parentheses, meanwhile, the content in parentheses should display the filter, as shown in the screenshot below.

Because the one in parentheses is the actual active part, we hid the part before it to avoid showing duplicate content. However, it seems the parentheses are not displayed on your side, so I am wondering if hiding the first part was a good choice.

2. To quickly unblock your progress,

the FileOpenPicker.FileTypeChoices in 2.0-experimental2 can be a mitigation, it allows us to customize both the label and filters.

[DinahK-2SO]

Oh I know what happend! The file name extension is not shown on your side!

Hey lhak , would you please enable this? You will see the extensions in brackets then.

And NICE Catch! This is indeed a subtle bug. I will add the label back to FileTypeFilters!

[lhak]

Dinah Xiaoman G (@DinahK-2SO) Yes, I can confirm that this is indeed the issue and toggling that option shows the labels

[DinahK-2SO]

Hi lhak , thanks for reporting this issue! The fixed is released in WinAppSDK >=1.8.4