//消息提醒（从手机屏幕顶部向下滑动，出现的提示消息）
NotificationC: TNotificationCenter; 
procedure TNotificationsForm.btnSendNotificationImmediatelyClick(
  Sender: TObject);
var
  Notification: TNotification;
begin
  { verify if the service is actually supported }
  if NotificationC.Supported then
  begin
    Notification := NotificationC.CreateNotification;
    try
      Notification.Name := 'MyNotification';
      Notification.AlertBody := 'Delphi for Mobile is here!';
      Notification.FireDate := Now; //可修改发送消息时间
      { Send notification in Notification Center }
      NotificationC.ScheduleNotification(Notification);
      { also this method is equivalent }
      // NotificationService.PresentNotification(Notification);
    finally
      Notification.DisposeOf;
    end;
  end
end;
  if NotificationC.Supported then
    NotificationC.CancelNotification('MyNotification'); //取消消息
    NotificationC.CancelAll; //取消所有消息