GetDpiForMonitor with Delphi 7 for per-monitor DPI awareness

Question

The WinAPI function GetDpiForMonitor doesn't have a header translation for Delphi 7 and searching the internet I could not find one.

If anyone has sample code showing how to use this WinAPI function from Delphi 7, that would help greatly.

Answer 1

Here's how to dynamically load the DLL and call the function in Delphi 7:

Type
  TMONITOR_DPI_TYPE = (
    MDT_EFFECTIVE_DPI {= 0},
    MDT_ANGULAR_DPI   {= 1},
    MDT_RAW_DPI       {= 2},
    MDT_DEFAULT       {= MDT_EFFECTIVE_DPI });

var
  dpiX              : UINT;
  dpiY              : UINT;
  ErrCode           : HResult;
  hShcore           : THandle;
  GetDpiForMonitor  : function(monitor: HMONITOR; dpiType: TMONITOR_DPI_TYPE; var dpi, dpiY: UINT): HRESULT; stdcall;

begin
  hShcore := GetModuleHandle('Shcore');
  If hShcore <> 0 then GetDpiForMonitor := GetProcAddress(hShcore,'GetDpiForMonitor');
  If @GetDpiForMonitor <> nil then 
    ErrCode := GetDpiForMonitor(Monitor.Handle,MDT_EFFECTIVE_DPI,dpiX,dpiY);
end;