问题
I am currently using a UICollectionView with a header, and am wondering how to animate and expand the header height when required.
I'm trying to emulate the functionality found in the Expedia app for iPhone, where tapping the image expands the header cell to reveal the image in the centre:
I've been trying this for a while so any suggestions would be great.
来源：https://stackoverflow.com/questions/32933476/animate-uicollectionview-header-height-change