Does WPF Per Monitor DPI awareness really work by default?

Starting from Windows 10 version 1607 (Anniversary Update) and later, WPF (Windows Presentation Foundation) applications support automatic per-monitor DPI awareness by default. This means that WPF applications can render correctly on high DPI displays without requiring additional modifications or code changes.

When a WPF application is launched on a system with multiple monitors having different DPI settings, the application will automatically scale its UI elements and content to match the DPI of each monitor. This ensures that the application appears crisp and properly sized on each display.

However, there are a few considerations to keep in mind:

1. Per-Monitor DPI Awareness Mode: To take full advantage of per-monitor DPI awareness in WPF, you need to specify the appropriate DPI awareness mode in the application manifest. By default, the manifest is set to "PerMonitorV2" starting from .NET Framework 4.8 and later. This mode enables WPF to handle per-monitor DPI scaling correctly.

2. WPF Version: Make sure you are using a version of the .NET Framework and WPF that supports per-monitor DPI awareness. Starting from .NET Framework 4.6.2 and later, WPF includes enhanced DPI support.

3. Per-Monitor DPI Testing: Test your WPF application on different monitors with varying DPI settings to verify that the UI scales correctly. Monitor scaling and DPI settings can be adjusted in the Windows Display settings.

While per-monitor DPI awareness in WPF works by default, there may still be scenarios where additional adjustments or code modifications are required to handle specific UI elements or custom controls properly. It's recommended to thoroughly test your WPF application on various DPI settings and monitor configurations to ensure optimal behavior.

For more detailed information and guidelines, refer to the official Microsoft documentation on High DPI in WPF applications: https://docs.microsoft.com/en-us/dotnet/framework/wpf/advanced/high-dpi-support