段尾的显示隐藏UICollectionReusableView

// 段尾高度     这一句话就ok

- (CGSize)collectionView:(UICollectionView*)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section{

    return  section==self.selectIndex?CGSizeMake(SCREEN_WIDTH,  SCREEN_WIDTH * 0.36):CGSizeMake(SCREEN_WIDTH,  0);

}

// selectIndex 当前选中索引

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {    

self.selectIndex = (int)indexPath.section;   

[self.collectionView reloadData];

}