对话框：
1、https://github.com/saiwu-bigkoo/Android-AlertView
https://github.com/saiwu-bigkoo/Android-AlertView/blob/master/preview/alertviewdemo.gif
2、 Activity 滑动返回
https://github.com/bingoogolapple/BGASwipeBackLayout-Android
https://www.jianshu.com/p/80d6f399f75b