我有一个 Collection View ，它将有一个 UILabel 和 2-5 个 UIButton。

我希望根据每个单元格显示多少个按钮来调整单元格的大小。我知道每个按钮的高度大约为 100。

class myViewController: UIViewController {

    var myCollectionView: UICollectionView!

    override func viewDidLoad() {
        super.viewDidLoad()

        let layout = UICollectionViewFlowLayout()
        layout.sectionInset = UIEdgeInsets(top: 0, left: 0, bottom: 100, right: 0) // add spacing to the bottom
        layout.itemSize = CGSize(width: self.view.frame.width, height: 300)
        layout.scrollDirection = .vertical
        layout.minimumLineSpacing = 20
        layout.minimumInteritemSpacing = 20

        myCollectionView=UICollectionView(frame: CGRect(x: 0, y: 0, width: self.view.frame.width, height: self.view.frame.height), collectionViewLayout: layout)
        myCollectionView.delegate=self
        myCollectionView.dataSource=self
        myCollectionView.register(MyCollectionViewCell.self, forCellWithReuseIdentifier: "Cell")
        myCollectionView.alwaysBounceVertical = false
        myCollectionView.showsVerticalScrollIndicator = false
        myCollectionView.translatesAutoresizingMaskIntoConstraints=false
        myCollectionView.backgroundColor=UIColor.white
        myCollectionView.isPagingEnabled = false

        loadViews()
    }

    func loadViews() {
        self.view.addSubview(myCollectionView)
        myCollectionView.topAnchor.constraint(equalTo: self.view.topAnchor).isActive=true
        myCollectionView.leftAnchor.constraint(equalTo: self.view.leftAnchor).isActive=true
        myCollectionView.rightAnchor.constraint(equalTo: self.view.rightAnchor).isActive=true
        myCollectionView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor).isActive=true

    }

}

注意上面的代码块有 layout.itemSize = CGSize(width: self.view.frame.width, height: 300) 这对 3 个按钮很有效 (3*100 = 300) .

然后在设置我的单元格类时，我创建了我的按钮，然后根据变量(在底部)确定它们的可见性。

class MyCollectionViewCell: UICollectionViewCell {
    var btn1: UIButton!
    var btn2: UIButton!
    var btn3: UIButton!
    var btn4: UIButton!
    var btn5: UIButton!

   override init(frame: CGRect) {
        super.init(frame: frame)

        setupViews()
    }

    func setupViews() {

        addSubview(lblQue)
        lblQue.topAnchor.constraint(equalTo: self.topAnchor, constant: 30).isActive=true
        lblQue.leftAnchor.constraint(equalTo: self.leftAnchor, constant: 12).isActive=true
        lblQue.rightAnchor.constraint(equalTo: self.rightAnchor, constant: -12).isActive=true
        lblQue.heightAnchor.constraint(equalToConstant: 50).isActive=true

        let btnWidth: CGFloat = 650
        let btnHeight: CGFloat = 65
        btn1 = getButton(tag: 0)
        addSubview(btn1)
        NSLayoutConstraint.activate([btn1.topAnchor.constraint(equalTo: lblQue.bottomAnchor, constant: 10), btn1.leftAnchor.constraint(equalTo: self.centerXAnchor, constant: -300), btn1.widthAnchor.constraint(equalToConstant: btnWidth), btn1.heightAnchor.constraint(equalToConstant: btnHeight)])
        btn1.addTarget(self, action: #selector(btnOptionAction), for: .touchUpInside)

        btn2 = getButton(tag: 1)
        addSubview(btn2)
        NSLayoutConstraint.activate([btn2.topAnchor.constraint(equalTo: btn1.bottomAnchor, constant: 10), btn2.leftAnchor.constraint(equalTo: self.centerXAnchor, constant: -300), btn2.widthAnchor.constraint(equalToConstant: btnWidth), btn2.heightAnchor.constraint(equalToConstant: btnHeight)])
        btn2.addTarget(self, action: #selector(btnOptionAction), for: .touchUpInside)

        btn3 = getButton(tag: 2)
        addSubview(btn3)
        NSLayoutConstraint.activate([btn3.topAnchor.constraint(equalTo: btn2.bottomAnchor, constant: 10), btn3.leftAnchor.constraint(equalTo: self.centerXAnchor, constant: -300), btn3.widthAnchor.constraint(equalToConstant: btnWidth), btn3.heightAnchor.constraint(equalToConstant: btnHeight)])
        btn3.addTarget(self, action: #selector(btnOptionAction), for: .touchUpInside)

        btn4 = getButton(tag: 3)
        addSubview(btn4)
        NSLayoutConstraint.activate([btn4.topAnchor.constraint(equalTo: btn3.bottomAnchor, constant: 10), btn4.leftAnchor.constraint(equalTo: self.centerXAnchor, constant: -300), btn4.widthAnchor.constraint(equalToConstant: btnWidth), btn4.heightAnchor.constraint(equalToConstant: btnHeight)])
        btn4.addTarget(self, action: #selector(btnOptionAction), for: .touchUpInside)

        btn5 = getButton(tag: 4)
        addSubview(btn5)
        NSLayoutConstraint.activate([btn5.topAnchor.constraint(equalTo: btn4.bottomAnchor, constant: 10), btn5.leftAnchor.constraint(equalTo: self.centerXAnchor, constant: -300), btn5.widthAnchor.constraint(equalToConstant: btnWidth), btn5.heightAnchor.constraint(equalToConstant: btnHeight)])
        btn5.addTarget(self, action: #selector(btnOptionAction), for: .touchUpInside)
    }

    func getButton(tag: Int) -> UIButton {
        let btn=UIButton()
        btn.tag=tag
        btn.setTitle("Option", for: .normal)
        btn.setTitleColor(UIColor.black, for: .normal)
        btn.backgroundColor=UIColor.white
        btn.layer.borderWidth=1
        btn.layer.borderColor=UIColor.darkGray.cgColor
        btn.layer.cornerRadius=5
        btn.clipsToBounds=true
        btn.translatesAutoresizingMaskIntoConstraints=false
        return btn
    }

    let lblQue: UILabel = {
        let lbl=UILabel()
        lbl.text="This is a question and you have to answer it?"
        lbl.textColor=UIColor.black
        lbl.textAlignment = .center
        lbl.font = UIFont.systemFont(ofSize: 20)
        lbl.numberOfLines=4
        lbl.translatesAutoresizingMaskIntoConstraints=false
        return lbl
    }()

    var myVariable: MyClassIMade? {
        didSet {
             // go through and determine button Text and Visibility of each button
             // i.e. 
             // if 1>0 { 
             //     btn3.visible = false
             // } else {
             //     btn3.visible = true
             // }

        }
    }

那么我如何确定有多少按钮可见，以确定每个部分的单元格大小？

最佳答案

这样的事情怎么样？只需将所有按钮放在一个数组中，然后遍历它们以检查哪些按钮被隐藏，哪些没有。你可以使用 .isHidden 隐藏和显示它们，然后检查哪个是隐藏的并返回数字..

示例函数:

func getButtonsCount(buttons: [UIButton]) -> Int{
    //A counter to get how many button are not hidden
    var count = Int()
    //A Loop to check which buttons are hidden and increment the counter
    for button in buttons {
        if button.isHidden == true {
            count += 1
        }
    }

    return count
}

关于ios - 根据按钮数量设置 CollectionView 单元格高度，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/56945371/