仿Nice卡片滑动
The initialization is very simple. Just like the sample below:
DWFlowLayout *layout = [[DWFlowLayout alloc] init];
//设置是否需要分页
[layout setPagingEnabled:YES];
self.collectionView.collectionViewLayout = layout;
//为垂直缩放除以系数
static CGFloat const ActiveDistance = 350;
//越大,缩放越大。
static CGFloat const ScaleFactor = 0.05;