目录一、定时器是什么二、自定义定时器一、定时器是什么 定时器类似于我们生活中的闹钟，可以设定一个时间来提醒我们。
This may be a little unconventional way of asking for help but my code is running into null pointer runtime errors but the scope of the runtime error is too big to post onto stackoverflow. I really wa
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