我如何在UICollectionView的一个部分设置单元格间距?我知道有一个属性minimumInteritemSpacing，我已经将它设置为5.0，但间距仍然没有出现5.0。我已经实现了flowout委托方法。
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section
{
return 5.0;
}
我仍然没有得到想要的结果。我认为这是最小间距。有没有什么方法可以设置最大间距?
当前回答
最流行的答案的Swift版本。单元格之间的空格将等于cellSpacing。
class CustomViewFlowLayout : UICollectionViewFlowLayout {
let cellSpacing:CGFloat = 4
override func layoutAttributesForElementsInRect(rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
if let attributes = super.layoutAttributesForElementsInRect(rect) {
for (index, attribute) in attributes.enumerate() {
if index == 0 { continue }
let prevLayoutAttributes = attributes[index - 1]
let origin = CGRectGetMaxX(prevLayoutAttributes.frame)
if(origin + cellSpacing + attribute.frame.size.width < self.collectionViewContentSize().width) {
attribute.frame.origin.x = origin + cellSpacing
}
}
return attributes
}
return nil
}
}
其他回答
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;
}
试试下面的代码，确保每个项目之间的间距为5px:
- (UIEdgeInsets)collectionView:(UICollectionView *) collectionView
layout:(UICollectionViewLayout *) collectionViewLayout
insetForSectionAtIndex:(NSInteger) section {
return UIEdgeInsetsMake(0, 0, 0, 5); // top, left, bottom, right
}
- (CGFloat)collectionView:(UICollectionView *) collectionView
layout:(UICollectionViewLayout *) collectionViewLayout
minimumInteritemSpacingForSectionAtIndex:(NSInteger) section {
return 5.0;
}
上面vojtech-vrbka的解决方案是正确的，但它会触发一个警告:
警告:UICollectionViewFlowLayout缓存的帧不匹配索引路径-缓存值:这可能是因为流布局子类layout是修改UICollectionViewFlowLayout返回的属性而没有复制它们
下面的代码应该修复它:
class CustomViewFlowLayout : UICollectionViewFlowLayout {
let cellSpacing:CGFloat = 4
override func layoutAttributesForElementsInRect(rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
let original = super.layoutAttributesForElementsInRect(rect)
if let original = original {
let attributes = NSArray.init(array: original, copyItems: true) as! [UICollectionViewLayoutAttributes]
for (index, attribute) in attributes.enumerate() {
if index == 0 { continue }
let prevLayoutAttributes = attributes[index - 1]
let origin = CGRectGetMaxX(prevLayoutAttributes.frame)
if(origin + cellSpacing + attribute.frame.size.width < self.collectionViewContentSize().width) {
attribute.frame.origin.x = origin + cellSpacing
}
}
return attributes
}
return nil
}
}
如果你在创建一个水平集合视图，那么为了在单元格之间留出空间，你需要设置属性minimumlinespcing。
