Android/iOS
var
clientScreenScale : Single;
clientScreenSize : TSize;
clientScreenService : IFMXScreenService;
begin
if TPlatformServices.Current.SupportsPlatformService(IFMXScreenService, IInterface(clientScreenService)) then
clientScreenScale := clientScreenService.GetScreenScale
else
clientScreenScale := 1;
// The display device's width:
clientScreenSize.CX := Round(clientScreenService.GetScreenSize.X * clientScreenScale);
// The display device's height:
clientScreenSize.CY := Round(clientScreenService.GetScreenSize.Y * clientScreenScale);
end;