ios - 如何减少 UICollection 视图中的垂直间距
问题描述
我在UICollectionView
下面使用的是我的代码,如何删除垂直间距?我尝试设置UICollectionViewFlowLayout
但没有工作。
class ViewController: UIViewController {
@IBOutlet weak var cv: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
cv.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "cell")
let layout: UICollectionViewFlowLayout = UICollectionViewFlowLayout()
layout.scrollDirection = .vertical
layout.sectionInset = UIEdgeInsets(top: 5, left: 5, bottom: 5, right: 5)
let xx : CGFloat = (UIScreen.main.bounds.width / 8)
let yy : CGFloat = 6.0
layout.itemSize = CGSize(width: xx, height: yy)
layout.minimumInteritemSpacing = 0
layout.minimumLineSpacing = 1
cv!.collectionViewLayout = layout
}
}
extension ViewController: UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 70
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath)
if (indexPath.row/2 == 0) {
cell.backgroundColor = UIColor.blue.withAlphaComponent(12)
}
else if (indexPath.row/4 == 0) {
cell.backgroundColor = UIColor.blue.withAlphaComponent(0.5)
}
else{
cell.backgroundColor = UIColor.blue.withAlphaComponent(0.1)
}
return cell
}
}
解决方案
您的情况下的间距是由每个项目的尺寸 - 宽度,主要是 - 引起的。
所以你有这个代码来计算你的单件宽度:
let xx : CGFloat = (UIScreen.main.bounds.width / 8)
但是由于您有部分插图,因此您的计算必须更改,或者您必须删除插图,因此:
let xx : CGFloat = (UIScreen.main.bounds.width - 10 / 8)
// 10 = 5 left + 5 right is taken for section insets
或者,删除您的部分插图:
// layout.sectionInset = UIEdgeInsets(top: 5, left: 5, bottom: 5, right: 5)
如果你想给出前导/尾随边距,请改用集合约束,即用常量(比如 5)约束它的超级视图collectionView
的leadingAnchor
/ trailingAnchor
,那么你不必进行计算,因为你可以使用sizeForItem
委托方法和以这种方式返回计算:
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: collectionView.bounds.width / 8, height: 5.0)
}