procedure TAddOrderCamera.CameraActionExecute(Sender: TObject);
var
  Service: IFMXCameraService;
  Params: TParamsPhotoQuery;
begin
  if TPlatformServices.Current.SupportsPlatformService(IFMXCameraService, Service) then
  begin
    Params.Editable := False; //拍完照是否允许编辑
    // Specifies whether to save a picture to device Photo Library
    Params.NeedSaveToAlbum := False; //是否保存到系统相册
    Params.RequiredResolution := TSize.Create(2000, 2000);//拍照大小，每张照片有固定宽高比例，系统会自动处理，给它一个想要的大约值就行。
    Params.OnDidFinishTaking :=Self.CameraActionDidFinishTaking;//拍完照后触发的事件
    Service.TakePhoto(nil, Params);//打开相机，开始拍照
  end
  else
    ShowMessage('设备不支持拍照.');
end;