Windows 10 1903 Window Drag Issue

[HEIC-to-JPEG-Dev]

Hi, I just upgraded to Windows 10 1903 and noticed that using the titlebar to drag a window has a very high latency, lagging behind the cursor movements by seconds.

I'm using the AcrylicWindow with ExtendViewIntoTitleBar="True"

Thanks for any updates.

[Andrei-Lapusteanu]

Experiencing the same issue on my 1903 build, could not yet figure out a solution.

[vivaladan]

I've only just discovered FluentWPF but have hit this issue right away on 1903 with a super simple new app.

[sourcechord]

Hi, @DHitchenUK
Sorry for replying so late.
Thanks for the information.
I recognized your reporting issue.
I'm inspecting the behavior of FluentWPF in Windows10 19H1, and trying to fix it.
Please wait for a while.

[HEIC-to-JPEG-Dev]

@sourcechord, I just wanted to say thanks for the work you put in, it's very much appreciated.

[dsafa]

If you turn off transparency effects in the settings, it works like before. Of course this turns off blur for all windows apps however.

[sourcechord]

Hi, @DHitchenUK
Maybe, it is same as riverar/sample-win32-acrylicblur#2

FluentWPF uses undocumented Win32API(SetWindowCompositionAttribute method).

The reported behavior is caused by the change in the behavior of that API.
It seems that SetWindowCompositionAttribute API is broken in Windows10 1903.

Dragging problem occurs Windows10's emoji toolbar, too.
(that is shown by Win+period key)
And, these problem is reported in Feedback Hub.
https://aka.ms/AA4pzyf
https://aka.ms/AA4fmz7

Please upvote it 🙏

[ashelleyPurdue]

I'm still getting this issue even after updating to FluentWPF 0.7.0.

EDIT: Actually, this is strange. The issue doesn't occur on my work computer, but does still occur on my home computer. I'll try it again on my home computer to see if I did something wrong.

[ghost1372]

This bug seems to be fixed in version 1903 (18362.267)

[0xCA]

This bug seems to be fixed in version 1903 (18362.267)

18362.295, still here

[JVimes]

Is this supposed to be open? 637ea17 did not fix it for me (Windows 1903, OS build 18995.1)

[Armin2208]

In 1909, or a new cumulative update, the problems are again present.