定时闹铃，每隔N分钟重复闹铃，显示剩下多少秒，自定义音乐。

适合初学者，如你对源码有改进的地方请联系：kevinmitnice@gmail.com-Timing alarm, repeat alarm every N minutes, indicating the number of seconds remaining, since the definition of music. Suitable for beginners, such as your local source for improvement please contact: kevinmitnice@gmail.com