How do I convert a WPF size to physical pixels?

Question

What\'s the best way to convert a WPF (resolution-independent) width and height to physical screen pixels?

I\'m showing WPF content in a WinForms Form (via ElementHo

Answer 1

I found a way to do it, but I don't like it much:

using (var graphics = Graphics.FromHwnd(IntPtr.Zero))
{
    var pixelWidth = (int) (element.DesiredSize.Width * graphics.DpiX / 96.0);
    var pixelHeight = (int) (element.DesiredSize.Height * graphics.DpiY / 96.0);
    // ...
}

I don't like it because (a) it requires a reference to System.Drawing, rather than using WPF APIs; and (b) I have to do the math myself, which means I'm duplicating WPF's implementation details. In .NET 3.5, I have to truncate the result of the calculation to match what ElementHost does with AutoSize=true, but I don't know whether this will still be accurate in future versions of .NET.

This does seem to work, so I'm posting it in case it helps others. But if anyone has a better answer, please, post away.