android 拖拽listview

看源码：

Pull-to-Refresh.Rentals-Android

https://github.com/Yalantis/Pull-to-Refresh.Rentals-Android

Android-PullToRefresh

https://github.com/chrisbanes/Android-PullToRefresh

拿ListView分析

Pull-to-Refresh.Rentals-Android 拖拽view继承自linearlayout，拖拽方式是头尾添加定高的view 控制整个linearlayout内部滑动 

Android-PullToRefresh 拖拽view继承自viewgroup，拖拽方式是手势获取距离后调用 mTarget.offsetTopAndBottom(offset);设置偏移量控制