iphone - IOS：在 UICollectionView 单元格上添加叠加图像

Question

我UICollectionView用来生成图片库。我在UIImage里面UICollectionView Cell用来加载图片。我需要UICollectionView Cell通过长按（而不是单击）进行选择。

Answer 1

只需拿起didSelectItemAtIndexPath委托回调，抓取单元格，然后添加图像作为子视图。

-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
    YourCollectionViewCell *cell = (YourCollectionViewCell*)[collectionView cellForItemAtIndexPath:indexPath];
    UIImageView *yourImageView = [[UIImageView alloc]initWithFrame:CGRectMake(x, y, width, height)];//whichever frame you want it to appear at
    yourImageView.image = [UIImage imageNamed:@"yourImageName"];//set the image
    [cell.yourBaseImage addSubview:yourImageView];//or add it to whatever part of the cell you want
}

或者，只需在 Storyboard 中设置一个隐藏的 imageView。然后取消隐藏并将图像设置在里面didSelectItemAtIndexPath。