Thumbnails are not showing up for Cloud-only files (Only metadata is cached on disk)

[viswanathr88]

[lmadhavan]

This seems to be an issue with the Windows thumbnail API not returning a real thumbnail for cloud files. The call doesn't actually fail, it just returns a placeholder image which makes this tricky to even detect from the app. Generating custom thumbnails for all files will likely result in poor performance.

[lmadhavan]

I was able to reproduce this with a test folder in OneDrive that was not available locally. Initially, File Explorer has the same issue where it only displays the placeholder. However, as soon as I go inside the folder, a thumbnail is generated even though the file has still not been downloaded. Once the thumbnail has been generated, it shows up in Fotografix as well.

[lmadhavan]

Opened an issue with the Windows App SDK team: microsoft/WindowsAppSDK#1874

[riverar]

Some additional guidance that may help https://docs.microsoft.com/en-us/windows/uwp/files/quickstart-determining-availability-of-microsoft-onedrive-files. Getting that API changed or new APIs added is probably going to be nearly impossible at this late stage for UWP.