How Can I call RuntimeHostConfigurationOption OnStartup of a WPF (C#) application in .NET 8?

MERUN KUMAR MAITY 576

Hi there, I have a WPF application where the UI is a very important thing and heart of the application. Due to some UI elements requirements I have some custom RuntimeHostConfigurationOption which I put in my WPF application through the *.csproj file.

I just put the new item group into the *.csproj file. And Part of my *.csproj file Code looks like this :

<Project>
...
<ItemGroup>
   <RuntimeHostConfigurationOption Include="Switch.System.Windows...." Value="true" />
   <RuntimeHostConfigurationOption Include="Switch.System.IO......." Value="false" />
</ItemGroup>
...
</Project>

And after that I build my WPF project in Visual Studio 2022 and surprisingly my Application works as expected. But there only one problem, this RuntimeHostConfigurationOption is not called on Application start up if I run my WPF application at a different Laptop with different screen size and different configuration, my Application somehow breaks the way it's performed.

This RuntimeHostConfigurationOption is only works on my development Laptop but it's not work if I change my Computer system or screens.

So, my question is, is there any way to call this RuntimeHostConfigurationOption OnStartup of my WPF application so that my WPF Application is forcefully use this settings each and every time when it start it does not matter it runs on my Development monitor or any other Computer systems.

Hongrui Yu-MSFT 1,605 Reputation points Microsoft Vendor

2024-09-12T09:25:18.66+00:00

Hi,@MERUN KUMAR MAITY. Welcome to Microsoft Q&A.

I'm not quite sure what you defined RuntimeHostConfigurationOption as. Could you please share or describe more clearly what RuntimeHostConfigurationOption is?
MERUN KUMAR MAITY 576 Reputation points

2024-09-14T09:17:44.62+00:00

Thanks for your comment. I want to request you to see this Developer Community Post, Here people use RuntimeHostConfigurationOption in *.csproj file.

https://developercommunity.visualstudio.com/t/dpiawareness-donotscalefordpichanges-not-working-f/1605189
Hongrui Yu-MSFT 1,605 Reputation points Microsoft Vendor

2024-09-16T09:20:57.6233333+00:00
Hi,@MERUN KUMAR MAITY.

To set the content of RuntimeHostConfigurationOption in code, you could use AppContext.SetSwitch.

public App() { AppContext.SetSwitch("Switch.System.Windows.DoNotScaleForDpiChanges", true); AppContext.SetSwitch("Switch.System.IO.UseLegacyPathHandling", false); }

Related Documents: AppContext.SetSwitch(String, Boolean) Method (System) | Microsoft Learn.

In addition, I tested the method provided in the link you provided, and the effect described in the link could not be achieved in both .Net 8 and .Net Framework 4.8 environments(In Windows 11).
MERUN KUMAR MAITY 576 Reputation points

2024-09-16T14:29:16.4366667+00:00

Thanks for your reply, but in my case it's working in my Windows 10 Laptop but not sure about Windows 11 because I never tested my App in Windows 11. I also tried your Code which is not working in my case.

We have to find another way to implement it. Forget about this RuntimeHostConfigurationOption

I hope you understand my main problem, if I run my App at another resolution or any other DPI rather than the developing Laptop monitor DPI and screen resolution, it's not working. The only last problem remain is that, otherwise every problem regarding the DPI is solved after I follow the link with RuntimeHostConfigurationOption.

Do you know any third party application that detect if a window is DPI Aware or not?

I already solved these DPI problems in Win32 desktop application but it seems like WPF Windows applications needs more tweaking.

If you interested to see those different DPI Aware version of Win32 application, I even ready to give you if you interested.

Hongrui Yu-MSFT 1,605 Microsoft Vendor

Hi,@MERUN KUMAR MAITY.

Due to policy, I cannot recommend third-party libraries, you could search by keyword.

In addition, after my test, the following code could successfully obtain the current DPI in WPF (.Net 8) and Windows 10 environment.


WindowInteropHelper windowInteropHelper = new WindowInteropHelper((MainWindow)App.Current.MainWindow);

IntPtr mainWindowHandle = windowInteropHelper.Handle;

Graphics graphics = Graphics.FromHwnd(mainWindowHandle);

float CurrentDpi_X = graphics.DpiX;

float CurrentDpi_Y = graphics.DpiY;

double dpiXRatio = CurrentDpi_X / 96;

double dpiYRatio = CurrentDpi_Y / 96;

MERUN KUMAR MAITY 576 Reputation points

2024-09-18T13:37:59.9066667+00:00

Thanks for your comment. Still, you don't get understand what I want to achieve. If you really interested to solve this problem forever for me then I am ready to share you my demo project, so that you can have a deep dive on it, and try to understand from basic and root of the problem.

Just say Yes or No.

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How Can I call RuntimeHostConfigurationOption OnStartup of a WPF (C#) application in .NET 8?

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