uses
  Androidapi.JNI.App;

function TAndroidServiceDM.AndroidServiceStartCommand(const Sender: TObject;
  const Intent: JIntent; Flags, StartId: Integer): Integer;
begin
   LThread := TThread.CreateAnonymousThread(procedure

    begin
       while true  do
       begin
          sleep(10000);
          DoNotification;
       end;
    end);
  LThread.FreeOnTerminate := False;
   LThread.Start;
   Result := TJService.JavaClass.START_STICKY; //   保持服务运行
end;

 procedure TAndroidServiceDM.DoNotification;
 var
  MyNotification: TNotification;
begin
MyNotification := NotificationCenter1.CreateNotification;
  try
    MyNotification.Name := 'xalion';
    MyNotification.Title := '时间到了'+formatdatetime('yyyy-mm-dd hh:nn:sss',now);
    MyNotification.AlertBody := '懒人都要起床了';
    MyNotification.FireDate:=now;
    NotificationCenter1.PresentNotification(MyNotification);
  finally
    MyNotification.Free;
  end;