Ios 为什么不显示集合可重用视图？

我想创建带有标题的UICollectionView。我在MainstryBoard上设置了集合可重用视图，但在设备上并没有显示任何内容。我试着搜索，但找不出它为什么没有出现。我

主楼板

在设备上

导入UIKit

class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate {


    @IBOutlet weak var collectionView: UICollectionView!

    var images = ["medal1","medal2","medal3","medal4","medal5","medal6","medal7","medal8","medal9","medal10","medal1","medal2","medal3","medal14"]

    var texts = ["hi","yes","hoo","such","hi","yes","hoo","such","hi","yes","hoo","such","hi","yes"]

    override func viewDidLoad() {
        super.viewDidLoad()



        collectionView.delegate = self
        collectionView.dataSource = self

    }

    public func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {

        return images.count
    }

    public func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CustomCell", for: indexPath) as! CustomCell

        cell.myImage.image = UIImage(named: images[indexPath.row])

        cell.achievementLabel.text = texts[indexPath.row]

        return cell

    }

    func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
        return 1
    }






}


import UIKit

class CollectionReusableView: UICollectionReusableView {

    @IBOutlet weak var reuseableVimage: UIImageView!
}


> import UIKit

class ViewController: UIViewController, UICollectionViewDelegate {


    @IBOutlet weak var collectionView: UICollectionView!

    var images = ["medal1","medal2","medal3","medal4","medal5","medal6","medal7","medal8","medal9","medal10","medal1","medal2","medal3","medal14"]

    var texts = ["hi","yes","hoo","such","hi","yes","hoo","such","hi","yes","hoo","such","hi","yes"]

    override func viewDidLoad() {
        super.viewDidLoad()



        collectionView.delegate = self


    }

    func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
        if kind == UICollectionElementKindSectionHeader {
            let view = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "HeaderView", for: indexPath)
            // do any programmatic customization, if any, here
            return view
        }
        fatalError("Unexpected kind")








}
}

集合视图的类 类CustomCell:UICollectionViewCell{

    @IBOutlet weak var myImage: UIImageView!

    @IBOutlet weak var achievementLabel: UILabel!

}

用于集合可重用视图的类 导入UIKit

class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate {


    @IBOutlet weak var collectionView: UICollectionView!

    var images = ["medal1","medal2","medal3","medal4","medal5","medal6","medal7","medal8","medal9","medal10","medal1","medal2","medal3","medal14"]

    var texts = ["hi","yes","hoo","such","hi","yes","hoo","such","hi","yes","hoo","such","hi","yes"]

    override func viewDidLoad() {
        super.viewDidLoad()



        collectionView.delegate = self
        collectionView.dataSource = self

    }

    public func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {

        return images.count
    }

    public func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CustomCell", for: indexPath) as! CustomCell

        cell.myImage.image = UIImage(named: images[indexPath.row])

        cell.achievementLabel.text = texts[indexPath.row]

        return cell

    }

    func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
        return 1
    }






}


import UIKit

class CollectionReusableView: UICollectionReusableView {

    @IBOutlet weak var reuseableVimage: UIImageView!
}


> import UIKit

class ViewController: UIViewController, UICollectionViewDelegate {


    @IBOutlet weak var collectionView: UICollectionView!

    var images = ["medal1","medal2","medal3","medal4","medal5","medal6","medal7","medal8","medal9","medal10","medal1","medal2","medal3","medal14"]

    var texts = ["hi","yes","hoo","such","hi","yes","hoo","such","hi","yes","hoo","such","hi","yes"]

    override func viewDidLoad() {
        super.viewDidLoad()



        collectionView.delegate = self


    }

    func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
        if kind == UICollectionElementKindSectionHeader {
            let view = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "HeaderView", for: indexPath)
            // do any programmatic customization, if any, here
            return view
        }
        fatalError("Unexpected kind")








}
}

---

尝试实现这一点。RayWenderlich中的一个例子可能对您有用：

---

您必须为种类的SupplementalElement实现

视图：

根据需要为
UICollectionElementKindSectionHeader
或
UICollectionElementKindSectionFooter
实施

func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
    if kind == UICollectionElementKindSectionHeader {
        let view = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "CollectionReusableView", for: indexPath) as! CollectionReusableView
        // do any programmatic customization, if any, here
        return view
    }
    fatalError("Unexpected kind")
}


确保IB中的标头可重用视图


适当的基类；以及
适当的“重用标识符”

在IB中，确保集合视图的“附件”在“节页眉”和“节页脚”旁边有复选标记（视情况而定）

swift 3中似乎有一些更改：/谢谢。我更新了代码，但现在屏幕上什么也没有显示。我检查了IB和附件，一切正常。假设没有警告，我可能会检查视图调试器，查看集合视图中是否有视图以及它们的帧。如果确实没有视图，那么我会设置breakpo在
UICollectionViewDataSource
方法中输入，并查看它们是否被调用以及它们返回的值。当我设置collectionView.dataSource=self时，它会崩溃。这是断点“let view=collectionView.dequeueReusableSupplementaryView（ofKind:kind，withReuseIdentifier:“CollectionReusableView”，for:indexPath）如！CollectionReusableView“”所示，标头视图没有匹配的“重用标识符”，或者标头的基类尚未设置。