Getting Screen Resolution

For years I have been using the API function GetSystemMetrics with Clearwin to get the current screen resolution, in order to decide on the size of graphics windows

Is there a better way? On one of my laptops GetSytemMetrics reports a screen resolution of 1280x720, but Windows says the resolution is actually 1920x1080

You may need to enable DP! awareness.

If you are using the latest release and your program has done something in ClearWin+ then DPI awareness will be on (Process_System_DPI_Aware) by default (but you need to be running Windows 8.1 or later).

Otherwise you can use the call

 i = SetDpiAwareness@(1)

See cwplus.enh for details.

Thanks, that works perfectly

What is the effect of a call SetDpiAwareness(1) if the operating system is earlier than Win 8.1 ?, i.e. can it be used safely in any program without checking the Windows version?

Yes it can be used safely. The function returns 0 if the operating system is before Windows 8.1.