pull to refresh with UIDynamic
a pull to refresh animation with UIDynamics 用UIDynamics做的下拉刷新动画
codes are kinda messy now,but I will reconstruct them later.However,you can still download and copy the codes to integrate them into your project.
代码现在有点乱 以后会重构 但是 可以直接复制代码到你的项目来运行
please feel free to modify 请自由修改