https://juejin.im/post/5bda6f276fb9a0226d18931f
https://juejin.im/post/5abca877f265da238155b6bc
https://juejin.im/post/599a58f6f265da247b4e756b
ios:https://www.jianshu.com/p/d12ec047ce52
android：https://www.cnblogs.com/whoislcj/p/6104015.html
https://juejin.im/post/5a950c36f265da4e8077ddf4