1.水珠按钮DropButton
https://github.com/qussers/dropButton

as.gif
2.城市选择
https://github.com/qussers/CitySelectViewController

ab.gif
1.水珠按钮DropButton
https://github.com/qussers/dropButton
2.城市选择
https://github.com/qussers/CitySelectViewController