回答Swift 3.0, Xcode 8

1.确保你设置了集合视图委托

class DashboardViewController: UIViewController {
    @IBOutlet weak var dashboardCollectionView: UICollectionView!

    override func viewDidLoad() {
        super.viewDidLoad()
        dashboardCollectionView.delegate = self
    }
}

2.实现uicollectionviewdelegatflowlayout协议，而不是UICollectionViewDelegate。

extension DashboardViewController: UICollectionViewDelegateFlowLayout {
    fileprivate var sectionInsets: UIEdgeInsets {
        return .zero
    }

    fileprivate var itemsPerRow: CGFloat {
        return 2
    }

    fileprivate var interitemSpace: CGFloat {
        return 5.0
    }

    func collectionView(_ collectionView: UICollectionView,
                        layout collectionViewLayout: UICollectionViewLayout,
                        sizeForItemAt indexPath: IndexPath) -> CGSize {
        let sectionPadding = sectionInsets.left * (itemsPerRow + 1)
        let interitemPadding = max(0.0, itemsPerRow - 1) * interitemSpace
        let availableWidth = collectionView.bounds.width - sectionPadding - interitemPadding
        let widthPerItem = availableWidth / itemsPerRow

        return CGSize(width: widthPerItem, height: widthPerItem)
    }

    func collectionView(_ collectionView: UICollectionView,
                        layout collectionViewLayout: UICollectionViewLayout,
                        insetForSectionAt section: Int) -> UIEdgeInsets {
        return sectionInsets
    }

    func collectionView(_ collectionView: UICollectionView,
                        layout collectionViewLayout: UICollectionViewLayout,
                        minimumLineSpacingForSectionAt section: Int) -> CGFloat {
        return 0.0
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
        return interitemSpace
    }
}

试试这个方法:

- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView
                    layout:(UICollectionViewLayout*)collectionViewLayout
    insetForSectionAtIndex:(NSInteger)section {

    UIEdgeInsets insets = UIEdgeInsetsMake(?, ?, ?, ?);

    return insets;
}

使用水平流布局，我也得到了10点之间的单元格间距。为了移除间距，我需要将minimumlinespespaces和minimumInterItemSpacing设置为零。

UICollectionViewFlowLayout *flow = [[UICollectionViewFlowLayout alloc] init];
flow.itemSize = CGSizeMake(cellWidth, cellHeight);
flow.scrollDirection = UICollectionViewScrollDirectionHorizontal;
flow.minimumInteritemSpacing = 0;
flow.minimumLineSpacing = 0;

此外，如果所有单元格大小相同，直接在流布局上设置属性比使用委托方法更简单、更有效。

我偶然发现了与op类似的问题。不幸的是，接受的答案不适合我，因为collectionView的内容不会正确居中。因此，我提出了一个不同的解决方案，只需要在collectionView中的所有项目都具有相同的宽度，这似乎是问题中的情况:

#define cellSize 90

- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
    float width = collectionView.frame.size.width;
    float spacing = [self collectionView:collectionView layout:collectionViewLayout minimumInteritemSpacingForSectionAtIndex:section];
    int numberOfCells = (width + spacing) / (cellSize + spacing);
    int inset = (width + spacing - numberOfCells * (cellSize + spacing) ) / 2;

    return UIEdgeInsetsMake(0, inset, 0, inset);
}

该代码将确保…minimumInteritemSpacing…将是每个collectionViewCell之间的精确间距，并进一步保证所有的单元格一起将在collectionView

我有问题与接受的答案，所以我更新了它，这是为我工作:

.h

@interface MaxSpacingCollectionViewFlowLayout : UICollectionViewFlowLayout
@property (nonatomic,assign) CGFloat maxCellSpacing;
@end

.m

@implementation MaxSpacingCollectionViewFlowLayout

- (NSArray *) layoutAttributesForElementsInRect:(CGRect)rect {
    NSArray *attributes = [super layoutAttributesForElementsInRect:rect];

    if (attributes.count <= 0) return attributes;

    CGFloat firstCellOriginX = ((UICollectionViewLayoutAttributes *)attributes[0]).frame.origin.x;

    for(int i = 1; i < attributes.count; i++) {
        UICollectionViewLayoutAttributes *currentLayoutAttributes = attributes[i];
        if (currentLayoutAttributes.frame.origin.x == firstCellOriginX) { // The first cell of a new row
            continue;
        }

        UICollectionViewLayoutAttributes *prevLayoutAttributes = attributes[i - 1];
        CGFloat prevOriginMaxX = CGRectGetMaxX(prevLayoutAttributes.frame);
        if ((currentLayoutAttributes.frame.origin.x - prevOriginMaxX) > self.maxCellSpacing) {
            CGRect frame = currentLayoutAttributes.frame;
            frame.origin.x = prevOriginMaxX + self.maxCellSpacing;
            currentLayoutAttributes.frame = frame;
        }
    }
    return attributes;
}

@end

如果你想在不影响实际单元格大小的情况下调整间距，这是最适合我的解决方案。#xcode 9 #tvOS11 #iOS11 #swift

在uicollectionviewdelegatflowlayout中，改变实现下一个方法，诀窍是你必须使用它们两个，文档并没有真正指向我去思考那个方向。: D

open func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
    return cellSpacing
}

public func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
    return cellSpacing
}