ios 在UICollectionView上最多选择4个图像

wqsoz72f 于 2022-12-15 发布在 iOS

关注(0)|答案(3)|浏览(170)

如果用户选择超过4张图像，则显示警报框。

-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
    UICollectionViewCell *secell = [collectionView cellForItemAtIndexPath:indexPath];

    if (indexPath.row == 4) {

        UIAlertView * alert =[[UIAlertView alloc ] initWithTitle:@"OK Dailog"
                                                         message:@"This is OK dialog"
                                                        delegate:self
                                               cancelButtonTitle:@"Cancel"
                                               otherButtonTitles: nil];
        [alert show];
    }

    else
    {
        UIImageView *imgselect = (UIImageView *)[secell viewWithTag:110];
        imgselect.image = [UIImage  imageNamed:@"selectimg.png"];
    }

}

ios

来源：https://stackoverflow.com/questions/25884767/select-maximum-4-images-on-uicollectionview

3条答案

按热度按时间

pcrecxhr1#

您应该检查所选项目的数量，而不是检查indexPath.row。可以尝试类似的操作

NSArray *selectedIndexPaths =  [collectionView  indexPathsForSelectedItems];

if (selectedIndexPaths.count > 4)
{
   // Show alert
}

赞(0）回复(0）举报 2022-12-15

vx6bjr1n2#

这应该在委托方法collectionView:shouldSelectItemAtIndexPath中设置

- (BOOL)collectionView:(UICollectionView *)collectionView shouldSelectItemAtIndexPath:(NSIndexPath *)indexPath {
    BOOL shouldSelect = collectionView.indexPathsForSelectedItems.count < 4;
    if (!shouldSelect) {
        // Show Alert
    }
    return shouldSelect;
}

赞(0）回复(0）举报 2022-12-15

cgyqldqp3#

适用于swift 5

func collectionView(_ collectionView: UICollectionView, shouldSelectItemAt indexPath: IndexPath) -> Bool {
        let shouldSelect = (collectionView.indexPathsForSelectedItems?.count ?? 0) < 4
        if !shouldSelect {
            // show alert here
        }
        return shouldSelect
    }

赞(0）回复(0）举报 2022-12-15

我来回答

ios 在UICollectionView上最多选择4个图像

3条答案

相关问题

热门标签

最新问答