iOS - 设置为 0 时 UICollectionView 间距仍然存在 - 如何设置单元格之间没有间距

Question

我有一个简单的 UICollectionView，我在 InterfaceBuilder 中设置了 0 间距，但是当我用单元格填充集合视图时，仍然有一些间距。为了实际看到一个间距为 0 的 collectionview 单元格，而不是将其设置为 0 间距，我需要做一些特别且不立即显而易见的事情吗？谢谢。

编辑*一些代码：

- (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath {

    UICollectionViewCell *cell = [cv dequeueReusableCellWithReuseIdentifier:@"Cell" forIndexPath:indexPath];

    cell.backgroundColor = [UIColor clearColor];

    UILabel *lbl = [[UILabel alloc] initWithFrame:CGRectMake(2, 2, cell.frame.size.width -4, cell.frame.size.height -4)];
    lbl.backgroundColor = [UIColor clearColor];
    lbl.font = [UIFont boldSystemFontOfSize:20];
    lbl.text = [NSString stringWithFormat:@"$%0.0f", [[amountsArray objectAtIndex:indexPath.row] floatValue]];
    lbl.textAlignment = NSTextAlignmentCenter;
    lbl.layer.borderWidth = 1;

    [cell addSubview:lbl];
    [lbl release];

    return cell;
}

Answer 1

查询的简单解决方案。将此添加到您的 viewController 的 .m 文件中：

-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
    ProductDetailViewController *HomeVC = [self.storyboard instantiateViewControllerWithIdentifier:@"ProductDetailView"];
    HomeVC.title = @"DemoProject";
    [self.navigationController pushViewController:HomeVC animated:YES];
}

- (UIEdgeInsets)collectionView:(UICollectionView*)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
    return UIEdgeInsetsMake(0, 0, 0, 0); // top, left, bottom, right
}

- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {

    return 0.0;
}

- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {
    return 0.0;
}

Answer 2

Swift 3 版本的@MihirOza 的解决方案

适用于水平和垂直集合视图

代码

// removing spacing
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
    return UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
    return 0.0
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
    return 0.0
}

Answer 3

您必须创建自定义UICollectionViewLayout。

单元格之间的间距将等于cellSpacing。

final class CustomFlowLayout: UICollectionViewFlowLayout {

    let cellSpacing: CGFloat = 0

    override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
        if let attributes = super.layoutAttributesForElements(in: rect) {
            for (index, attribute) in attributes.enumerated() {
                if index == 0 { continue }
                let prevLayoutAttributes = attributes[index - 1]
                let origin = prevLayoutAttributes.frame.maxX
                if (origin + cellSpacing + attribute.frame.size.width < self.collectionViewContentSize.width) {
                    attribute.frame.origin.x = origin + cellSpacing
                }
            }
            return attributes
        }
        return nil
    }

}

Answer 4

我解决了这个问题并得到了我想要的布局：

- (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath {

UICollectionViewCell *cell = [cv dequeueReusableCellWithReuseIdentifier:@"Cell" forIndexPath:indexPath];



    cell.backgroundColor = [UIColor clearColor];

    //clear any contents on the cell
    for (UIView *subView in [cell subviews]) {
    [subView removeFromSuperview];
    }


    //Label to put on the cell
    UILabel *lbl = [[UILabel alloc] initWithFrame:CGRectMake(2, 2, cell.frame.size.width -4, cell.frame.size.height -4)];
    lbl.backgroundColor = [UIColor clearColor];
    lbl.textColor = [UIColor colorWithRed:[CPExtras RGBtoPercent:70] green:[CPExtras RGBtoPercent:92] blue:[CPExtras RGBtoPercent:105] alpha:1];
    lbl.font = [UIFont boldSystemFontOfSize:20];
    lbl.text = @"100";
    lbl.textAlignment = NSTextAlignmentCenter;

    //Give the cell a border
    cell.layer.borderColor = [[UIColor colorWithRed:[CPExtras RGBtoPercent:70] green:[CPExtras RGBtoPercent:92] blue:[CPExtras RGBtoPercent:105] alpha:0.5] CGColor];
    cell.layer.borderWidth = 0.5;


    [cell addSubview:lbl];

    [lbl release];





return cell;
}

在 IB 中，我为 collectionview 设置了以下测量设置：

Answer 5

为了实际上有零空间，单元格的数量和它们的宽度应该可以被集合视图自己的宽度整除，例如 如果您一次有 5 个宽度为 100 像素的单元格，那么您的集合视图应该有 500 像素的宽度，如果它更大，那么它将强制单元格之间有一个空间。

Answer 6

[UICollectionViewFlowLayout minimumInteritemSpacing] 的 documentation 提到：

这个间距是用来计算一行可以放多少个item，但是在item个数确定后，实际间距可能会向上调整。

您可能需要实现自定义布局来执行此操作。可以在here 找到文档，并在here 找到示例。