帮着看下这个函数的意思

function DynamicResolution(X, Y: word): BOOL;
var
lpDevMode: TDeviceMode;
begin
Result := EnumDisplaySettings(nil,0,lpDevMode);
if Result then
begin
lpDevMode.dmFields := DM_PELSWIDTH Or DM_PELSHEIGHT;
lpDevMode.dmPelsWidth := X;
lpDevMode.dmPelsHeight := Y;
Result := ChangeDisplaySettings(lpDevMode, 0)=DISP_CHANGE_SUCCESSFUL;
end;
end;