ViewPagerX
ViewPager功能增强
https://github.com/JiangAndroidwork/BottomSheetViewPager https://github.com/kafumi/android-bottomsheet-viewpager
https://www.jianshu.com/p/7d3b5b0ee09f http://182.254.228.71/Android%E6%8E%A7%E4%BB%B6-ViewPager%E7%9A%84%E9%A2%84%E5%8A%A0%E8%BD%BD%E5%92%8C%E6%87%92%E5%8A%A0%E8%BD%BD/