Question

How can I get the DPI in WPF?

Answer 1

https://docs.microsoft.com/en-us/archive/blogs/jaimer/getting-system-dpi-in-wpf-app seems to work

PresentationSource source = PresentationSource.FromVisual(this);

double dpiX, dpiY;
if (source != null) {
    dpiX = 96.0 * source.CompositionTarget.TransformToDevice.M11;
    dpiY = 96.0 * source.CompositionTarget.TransformToDevice.M22;
}