The thumbnail in DO can not work with software setuped wihle in windows explorer works.
sorry, I have restarted my computer just now. Here is the thumbnail setup file from my friend.
缩略图插件.zip (5.1 MB)
With this software above setuped,windows explorer can get the ability to see the thumbnail of *.DST files like color.zip (1.8 KB) while DO can't.
Do you have time to improve it to make it works with *.DST as it in explorer.
What is this software? Where is it from? Or did your friend write it?
What is a DST file?
From my friend, it is a special-purpose in work which can only be edited by special software. But with the the software for thumbnail https://resource.dopus.com/uploads/short-url/wCbvYEoejyN51w2dSYNpUHp7PTP.zip setuped, the sample DST file https://resource.dopus.com/uploads/short-url/vvBeXYutJ0WvMrta2sxPf5NkQFL.zip can be thumbnailed.
You can have a try I prefer if time allowed.
If he implements a 64-bit IThumbnailProvider and registers it against the filetype in the registry correctly, it should work in Opus the same as in File Explorer.