如何根据设备主题更改 collectionview 单元格颜色（按照我的配色方案）

Question

概览：

我正在使用集合视图构建键盘扩展。我希望单元格根据设备主题 (light/dark) 改变颜色。目前，当我为我的 collectionview 单元格设置配色方案时，它们不起作用。我用“///”注释标记了我的代码中有问题的部分。

资源：

我找到了 this RayWenderlich project，我喜欢他们处理颜色变化的方式，所以我复制了它。

我的代码：

我有3个类:

键盘视图控制器
包含键盘按钮的自定义视图
自定义集合视图单元格

CollectionView 单元格

class KeyboardKeys: UICollectionViewCell {
    
    var defaultColor = UIColor.white
    var highlighColor = UIColor.lightGray.withAlphaComponent(0.6)
    
    let label: UILabel = {
        let iv = UILabel()
        iv.translatesAutoresizingMaskIntoConstraints = false
        iv.contentMode =  .scaleAspectFit
        iv.font = UIFont.systemFont(ofSize: 20)
        iv.clipsToBounds = true
        iv.numberOfLines = 1
        iv.textAlignment = .center
        
        return iv
    }()

    override init(frame: CGRect) {
        super.init(frame: .zero)
        commonInit()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        commonInit()
    }
    
    func commonInit() {
        contentView.addSubview(label)
        label.topAnchor.constraint(equalTo: contentView.topAnchor).isActive = true
        label.leftAnchor.constraint(equalTo: contentView.leftAnchor).isActive = true
        label.rightAnchor.constraint(equalTo: contentView.rightAnchor).isActive = true
        label.bottomAnchor.constraint(equalTo: contentView.bottomAnchor).isActive = true   
    }
    
    override func layoutSubviews() {
        super.layoutSubviews()
            backgroundColor = isHighlighted ? highlighColor : defaultColor  
    }   
}

自定义视图

class lettersKeyboard: UIView, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout{
var keyView: UICollectionView!
 let letters = ["q", "w", "e", "r", "t", "y", "u", "i", "o", "p"]
 override init(frame: CGRect) {
        super.init(frame: frame)
        commonInit()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        commonInit()
        
    }
    
    private func commonInit(){
//If you find some errors it's because this is way different in my code. This is just a regulare  collection view anyway

    let layout = UICollectionViewFlowLayout()
    layout.scrollDirection = .vertical
        
    keyView = UICollectionView(frame: CGRect(x: 0.0, y: 0.0 , width: frame.width, height: 280), collectionViewLayout: layout)
    keyView.setCollectionViewLayout(layout, animated: true)
    keyView.isScrollEnabled = false
    keyView.register(KeyboardKeys.self, forCellWithReuseIdentifier: "collectionCellId")
    keyView.delegate = self
    keyView.dataSource = self
    addSubview(keyView)
}

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        10
    }
    
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = keyView.dequeueReusableCell(withReuseIdentifier: "collectionCellId", for: indexPath) as! KeyboardKeys
        cell.label.text = letters[indexPath.row]
        return cell
    }
    ///I guess something is wrong here 
    func setColorScheme(_ colorScheme: ColorScheme) {
      let colorScheme = CColors(colorScheme: colorScheme)
     
      for view in subviews {
        if let cell = view as? KeyboardKeys {
            cell.tintColor = colorScheme.buttonTextColor
            cell.defaultColor = colorScheme.keysDefaultColor
            cell.highlighColor = colorScheme.keysHighlightColor
      }
      }
    }
    
}

配色方案结构

enum ColorScheme {
    case dark
    case light
}

struct CColors {
    
    let keysDefaultColor: UIColor
    let keysHighlightColor: UIColor
    
    let buttonTextColor: UIColor
   
    
    init(colorScheme: ColorScheme) {
        switch colorScheme {
        case .light:
           
            keysDefaultColor = .systemRed
                //UIColor.white
            keysHighlightColor = UIColor.lightGray.withAlphaComponent(0.6)
         
            buttonTextColor = .black
           
        case .dark:
            
            keysDefaultColor = .systemBlue
                // UIColor.gray.withAlphaComponent(0.5)
            keysHighlightColor = UIColor.lightGray.withAlphaComponent(0.5)
            
            buttonTextColor = .white  
        }
    }
}

键盘视图控制器

class KeyboardViewController: UIInputViewController {
var letters : lettersKeyboard = {
      
        let m = lettersKeyboard(frame: .zero)
            m.translatesAutoresizingMaskIntoConstraints = false

            m.backgroundColor = .clear
            return m
        
}()
override func viewDidLoad() {
        super.viewDidLoad()
 
        view.addSubview(letters)
   
        letters.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
        letters.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
        letters.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
        letters.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
}
//The rest is the default inputvc stuff 

    ///Or here
    override func textDidChange(_ textInput: UITextInput?) {
        // The app has just changed the document's contents, the document context has been updated.
       
        let colorScheme:  ColorScheme
        let proxy = self.textDocumentProxy
        if proxy.keyboardAppearance == UIKeyboardAppearance.dark {
            colorScheme = .dark
        } else {
            colorScheme = .light
        }
        letters.setColorScheme(colorScheme)
    }
}

问题：

我不知道我做错了什么，因为我的代码适用于除 collectionview 单元格之外的所有内容。我想存在另一种做这些事情的方法。那么如何根据我的配色方案根据设备的主题更改我的 collectionView 单元格的颜色？

Answer 1

你真的应该重新加载集合视图，而不是试图找到作为键的子视图，然后更新它们。

将 colorScheme 模型传递给每个单元格，并在重新加载时设置颜色。

Answer 2

一个非常善良的人帮助我找到了这个解决方案。这里的问题是我忘记了视图的层次结构。

CollectionView 单元格

 override func layoutSubviews() {
        super.layoutSubviews()
           setupBackGround()
    } 
func setupBackGround(){
backgroundColor = isHighlighted ? highlighColor : defaultColor
}

键盘视图控制器


func setColorScheme(_ colorScheme: ColorScheme) {
      let colorScheme = CColors(colorScheme: colorScheme)
     
      for view in subviews {
         func setToRootView(view: UIView) {
                if let cell = view as? KeyboardKeys {
                    cell.tintColor = colorScheme.buttonTextColor
                    cell.defaultColor = colorScheme.keysDefaultColor
                    cell.highlighColor = colorScheme.keysHighlightColor
                    cell.setBackground()
                    return
                }
                guard view.subviews.count > 0 else {
                    return
                }
                view.subviews.forEach(setToRootView(view:))
            }
            setToRootView(view: self)
        }

如何根据设备主题更改 collectionview 单元格颜色（按照我的配色方案）

How to change collectionview cells color based on device theme (following my color scheme)

colors

ios

uicollectionview

swift

概览：

资源：

我的代码：

CollectionView 单元格

自定义视图

配色方案结构

键盘视图控制器

问题：

CollectionView 单元格

键盘视图控制器