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I had wanted to publish a new version of my app (WPF converted to UWP with Desktop Bridge) to the Microsoft Store, but it failed the certification with following warning:

  • File **.exe neither has PerMonitorV2 manifested in the manifest nor calls into DPI Awareness APIs for ex: user32!SetProcessDpiAwarenessContext or user32!SetThreadDpiAwarenessContext.
  • The app *** is not DPI Aware.

I have the following questions:

  1. First of all I had published the first version of my app at the end of the last year and there was no problems with the DPI awareness. So this is a new test?

  2. Since this is just a warning and all other tests are passed, this could be the reason why the certification process failed?

  3. So I tried to make my app DPI aware...

Based on this description I called into SetProcessDpiAwarenessContext function and checked with all of the four values. With unaware and System aware flags my app looked blurry, and with the Per Monitor flags looked good, but when I requested the screen size, it returned the original width and height, not counting the scale (I have a 150% scale), so my windows was positioned to a wrong part of the screen. The question is that if there are just those 4 flags to set and none of them works as the default (without setting anything), then what is the default setting?

Okay, here is listed 5 flags, but none of them are working as if there would be nothing set.

Thanks a lot!

Mehrzad Chehraz
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Attila Szász
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  • A WPF app calls SetProcessDPIAware(), but that isn't good enough to keep the store happy. To make yourself monitor-aware you do have to do [more work](https://learn.microsoft.com/en-us/windows/win32/hidpi/declaring-managed-apps-dpi-aware), you have to handle the notification you get when the window is moved to another monitor. It recommends using SetProcessDpiAwareness() instead of using the manifest, why you have trouble with it is not very clear but expected if the app gets started on another monitor. You have to handle WM_DPICHANGED. – Hans Passant Mar 06 '20 at 13:01
  • Warnings shouldn't block ingestion; did you try contacting Store Support? – Peter Torr - MSFT Mar 09 '20 at 00:18

1 Answers1

3

Finally I found the solution to the issue: Instead of trying to make my app DPI aware from the code by calling the corresponding methods from a system DLL, I had to add an app.manifest file to the WPF project. As I tried this way the issue related to the invalid screen size disappeared.

Here is an example what should contain this manifest file. A very important thing is that the Store didn't accepted the PerMonitor setting as it is in the example above. It must be changed to PerMonitorV2 (by the way this is what they asked in the error message as well).

By adding this settings to the project, it passed the certification on the Store. And surprisingly yes, this warning was the reason why the certification failed.

One more thing after adding the manifest file, it should be connected to the project. You can do it by adding the following code to the <your_project_name>.csproj file (example here):

<PropertyGroup>
  <ApplicationManifest>app.manifest</ApplicationManifest>
</PropertyGroup>

To see the whole picture, I also added the second step from this answer.

Enjoy!

Attila Szász
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