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UICollectionView的标题显示不正确。我在头文件中添加了一个UILabel,它应该显示节号。当我调试viewForSupplementaryElementOfKind时,一切看起来都不错。我查看了关于collectionView标题的不同教程,并且在代码中找不到该错误。 Swift UICollectionView标题显示不正确
这里是整个代码:
import UIKit
class ViewController: UIViewController {
var collectionView:UICollectionView!;
override func viewDidLoad() {
super.viewDidLoad()
let layout:UICollectionViewFlowLayout = UICollectionViewFlowLayout();
layout.sectionInset = UIEdgeInsets(top: 20, left: 20, bottom: 20, right: 20);
layout.itemSize = CGSize(width: 60, height: 60);
layout.headerReferenceSize = CGSize(width: CGRectGetWidth(self.view.bounds), height: 50);
collectionView = UICollectionView(frame: self.view.frame, collectionViewLayout: layout);
collectionView.dataSource = self;
collectionView.registerClass(UICollectionViewCell.self, forCellWithReuseIdentifier: "cell");
collectionView.registerClass(UICollectionReusableView.self, forSupplementaryViewOfKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "header");
collectionView.delegate = self;
self.view.addSubview(collectionView);
}
}
extension ViewController:UICollectionViewDataSource{
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 5;
}
func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
return 10
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("cell", forIndexPath: indexPath);
cell.backgroundColor = UIColor.whiteColor();
return cell;
}
func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {
let view = collectionView.dequeueReusableSupplementaryViewOfKind(kind, withReuseIdentifier: "header", forIndexPath: indexPath)
view.backgroundColor = UIColor.blueColor();
let label = UILabel(frame: view.frame);
label.text = String(indexPath.section);
label.font = UIFont(name: "helvetica", size: 40);
label.textAlignment = .Center;
view.addSubview(label);
return view;
}
}
这不是你的问题的根源,但它很重要:你并没有意识到'collectionView.dequeueReusableSupplementaryViewOfKind'返回一个_reusable_视图。这个词很重要。该视图可能与已用于其他标题的视图相同。如果是这样,你不想再次添加标签。 – matt