/// <summary>
/// Returns the scaling of the given screen.
/// </summary>
/// <param name="screen">The screen which scaling should be given back.</param>
/// <param name="dpiType">The type of dpi that should be given back..</param>
/// <param name="dpiX">Gives the horizontal scaling back (in dpi).</param>
/// <param name="dpiY">Gives the vertical scaling back (in dpi).</param>
internal static void GetDpi(this Screen screen,
NativeMethods.DpiType dpiType, out uint dpiX, out uint dpiY)
{
var point = new Point(screen.Bounds.Left + 1, screen.Bounds.Top + 1);
var hmonitor = NativeMethods.MonitorFromPoint(point,
NativeMethods.MONITOR_DEFAULTTONEAREST);
switch (NativeMethods.GetDpiForMonitor(hmonitor, dpiType, out dpiX,
out dpiY).ToInt32())
{
case NativeMethods.S_OK: return;
case NativeMethods.E_INVALIDARG:
throw new ArgumentException("Unknown error. See https://msdn.microsoft.com/en-us/library/windows/desktop/dn280510.aspx for more information.");
default:
throw new COMException("Unknown error. See https://msdn.microsoft.com/en-us/library/windows/desktop/dn280510.aspx for more information.");
}
}