20180705 fragment
https://www.cnblogs.com/chaowang/p/6180825.html
https://blog.csdn.net/xxkalychen/article/details/53728327
https://www.cnblogs.com/chaowang/p/6180825.html
https://www.cnblogs.com/chaowang/p/6180825.html
https://blog.csdn.net/xxkalychen/article/details/53728327
https://www.cnblogs.com/chaowang/p/6180825.html