Question

our delphi application can have multiple DirectX windows, often on multiple screens. up to now the user had to specify the fullscreen resolution using a dropdown with the supported resolutions. it would be very nice, if he could use a setting like ‘current’ which would be the resolution of the screen on which the window is.

we are using delphi with clootie directX headers. can someone give me a hint, how i would write a method using directX, winAPI or delphi methods to get the resolution of the current screen on which the window is?

kind regards,
thalm

Final Solution:

ok, delphi 2007 MultiMon.pas returns crap for GetMonitorInfo, so i found this method, which works for me, using the winAPI directly:

function GetRectOfMonitorContainingRect(const R: TRect): TRect;
{ Returns bounding rectangle of monitor containing or nearest to R }
type
  HMONITOR = type THandle;
  TMonitorInfo = record
    cbSize: DWORD;
    rcMonitor: TRect;
    rcWork: TRect;
    dwFlags: DWORD;
  end;
const
  MONITOR_DEFAULTTONEAREST = $00000002;
var
  Module: HMODULE;
  MonitorFromRect: function(const lprc: TRect; dwFlags: DWORD): HMONITOR; stdcall;
  GetMonitorInfo: function(hMonitor: HMONITOR; var lpmi: TMonitorInfo): BOOL; stdcall;
  M: HMONITOR;
  Info: TMonitorInfo;
begin
  Module := GetModuleHandle(user32);
  MonitorFromRect := GetProcAddress(Module, 'MonitorFromRect');
  GetMonitorInfo := GetProcAddress(Module, 'GetMonitorInfoA');
  if Assigned(MonitorFromRect) and Assigned(GetMonitorInfo) then begin
    M := MonitorFromRect(R, MONITOR_DEFAULTTONEAREST);
    Info.cbSize := SizeOf(Info);
    if GetMonitorInfo(M, Info) then begin
      Result := Info.rcMonitor;
      Exit;
    end;
  end;
  Result := GetRectOfPrimaryMonitor(True);
end;

Answer 1

var
  MonInfo: TMonitorInfo;
begin
  MonInfo.cbSize := SizeOf(MonInfo);
  GetMonitorInfo(MonitorFromWindow(Handle, MONITOR_DEFAULTTONEAREST), @MonInfo);
  ShowMessage(Format('Current resolution: %dx%d',
              [MonInfo.rcMonitor.Right - MonInfo.rcMonitor.Left,
               MonInfo.rcMonitor.Bottom - MonInfo.rcMonitor.Top]));