UICollectionView－事件

1。UICollectionViewCell状态
highlighted：手指按下没抬起来
selected：手指按下，之后抬起来
selectedBackgroundView：选中背景
2。<UICollectionViewDelegate> 事件
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath //选中
collectionView:didDeselectItemAtIndexPath:
- (void)collectionView:(UICollectionView *)collectionView didHighlightItemAtIndexPath:(NSIndexPath *)indexPath //高亮
collectionView:didUnhighlightItemAtIndexPath:
e.g.
const NSTimeInterval kAnimationDuration = 0.20; //作为后续的动画时间，如放大，缩小的动画持续时间
- (void) collectionView:(UICollectionView *)collectionView didHighlightItemAtIndexPath:(NSIndexPath *)indexPath{
UICollectionViewCell *selectedCell = [collectionView cellForItemAtIndexPath :indexPath];

[UIView animateWithDuration:kAnimationDuration animations:^{

selectedCell.transform = CGAffineTransformMakeScale(2.0f, 2.0f); //放大，参数：宽高缩放比例

}];

}

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

UICollectionViewCell *selectedCell = [collectionView cellForItemAtIndexPath:indexPath];

[UIView animateWithDuration:kAnimationDuration animations:^{

selectedCell.transform = CGAffineTransformMakeScale(1.0f, 1.0f);

}];

}

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

UICollectionViewCell *selectedCell = [collectionView cellForItemAtIndexPath:indexPath];
//类似淡入淡出效果的动画效果， cell的awakeFromNib是在加载时会调用的初始化（在cell是xib文件时）

[UIView animateWithDuration:kAnimationDuration animations:^{

selectedCell.alpha = 0.0f; //透明

} completion:^(BOOL finished) {

[UIView animateWithDuration:kAnimationDuration animations:^{

selectedCell.alpha = 1.0f;

}];

}];

}