在不同的swift文件中調用超類進入子類

我遇到了創建超類，然後在子類中重寫它的問題。我在iOS上仍然是一個初學者，並且很快，所以如果我的解釋和措辭是錯誤的，我會提前道歉。下面我使用的代碼，請參閱：在不同的swift文件中調用超類進入子類

// created super class in .swiftfile A 
class BaseCell: UICollectionViewCell { 
    override init(frame: CGRect) { 
     super.init(frame: frame) 
     setupViews() 
    } 

    func setupViews() { 

    } 

    required init?(coder aDecoder: NSCoder) { 
     fatalError("init(coder:) has not been implemented") 
    } 
} 



// swiftfile B trying to call the superclass 

class MenuBar: UIView, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout { 


    lazy var collectionView: UICollectionView = { 
     let layout = UICollectionViewFlowLayout() 
     let cv = UICollectionView(frame: .zero, collectionViewLayout: layout) 
     cv.backgroundColor = UIColor.rgb(230, green: 32, blue: 31) 
     cv.dataSource = self 
     cv.delegate = self 
     return cv 
    }() 

    let cellId = "cellId" 

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

     collectionView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: cellId) 

     addSubview(collectionView) 
     addConstraintsWithFormat("H:|[v0]|", views: collectionView) 
     addConstraintsWithFormat("V:|[v0]|", views: collectionView) 

    } 

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int { 
     return 4 
    } 

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell { 
     let cell = collectionView.dequeueReusableCell (withReuseIdentifier: cellId, for: indexPath) 
     // ** when I uncomment this the blue cells show up cell.backgroundColor = UIColor.blue 
     return cell 

    } 

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize { 
     return CGSize(width: frame.width/4, height: frame.height) 

    } 

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat { 
     return 0 
    } 

    required init?(coder aDecoder: NSCoder) { 
     fatalError("init(coder:) has not been implemented") 
    } 

} 

//subclass I am trying to call super class into 
class MenuCell: BaseCell { 

    override func setupViews() { 
     super.setupViews() 
     // *** but when I run the app these yellow cells do not show 
     backgroundColor = UIColor.yellow 
    } 
}

來源

2017-01-26 user3708224

您註冊的單元類類型爲'UICollectionViewCell.self'而不是'MenuCell.self' ... – Hamish

謝謝！解決了它 – user3708224

在cellForItemAt方法，你是不是您鑄造細胞自定義類

guard let cell = collectionView.dequeueReusableCell (withReuseIdentifier: cellId, for: indexPath) as? BaseCell else { 
    return UICollectionViewCell() 
}

哈米什還指出，你沒有註冊您的自定義cell

來源

2017-01-26 19:50:52 David

在不同的swift文件中調用超類進入子類

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