上次做了个功能不是很完善的给朋友发到网上咯！～

本次多了个文本流的跟踪显示朗读功能，

没办法老师硬是要求实现这个功能！人有时是要有压力才有动力的～

在此奉上代码相互学习。-Last made a feature is not very good friend sent to the online strategy! ~ The more a read the text flow feature tracking display, can not he just asked the teacher to achieve this function! Sometimes the pressure is to have only driven ~ learn from each other in this offer code.