UIKit代码创建的UIButton点击无响应问题求助

我正在使用Swift UIKit以代码方式开发一款绘图APP。已为Pencil枚举中定义的每种颜色创建了对应的UIButton，按钮能正常显示，但点击时毫无反应，控制台甚至没有打印点击事件的信息。@objc方法buttonClicked本应给画笔分配对应按钮的颜色，但完全不生效。

相关代码 #

画笔属性定义

var lastPoint = CGPoint.zero
var color = UIColor.black
var brushWidth: CGFloat = 10.0
var opacity: CGFloat = 1.0
var swiped = false

点击方法

@objc func buttonClicked(_ sender: UIButton){
    guard let pencil = Pencil(tag: sender.tag) else {
      return
    }
    
    color = pencil.color
 
    if pencil == .eraser {
      opacity = 1.0
    }
    print("button Clicked")
}

创建颜色按钮函数

func createColorButton() -> [UIButton]{
    
    var buttons: [UIButton] = []
    for pencilCase in Pencil.allCases {
        let button = UIButton(frame: CGRect(x: 50, y: 50, width: 100, height: 100))
        button.backgroundColor = pencilCase.color
        button.tag = pencilCase.hashValue
        button.addTarget(self, action: #selector(self.buttonClicked(_:)), for: .touchUpInside)

        buttons.append(button)
    }
 return buttons
}

Pencil枚举定义

enum Pencil: CaseIterable {
    
    case black
    case grey
    case red
    case darkblue
    case lightBlue
    case darkGreen
    case lightGreen
    case brown
    case orange
    case yellow
    case eraser
    
    init?(tag: Int) {
        switch tag {
        case 1:
          self = .black
        case 2:
          self = .grey
        case 3:
          self = .red
        case 4:
          self = .darkblue
        case 5:
          self = .lightBlue
        case 6:
          self = .darkGreen
        case 7:
          self = .lightGreen
        case 8:
          self = .brown
        case 9:
          self = .orange
        case 10:
          self = .yellow
        case 11:
          self = .eraser
        default:
          return nil
        }
      }
    // 颜色属性
    var color: UIColor {
      switch self {
      case .black:
        return .black
      case .grey:
        return UIColor(white: 105/255.0, alpha: 1.0)
      case .red:
        return UIColor(red: 1, green: 0, blue: 0, alpha: 1.0)
      case .darkblue:
        return UIColor(red: 0, green: 0, blue: 1, alpha: 1.0)
      case .lightBlue:
        return UIColor(red: 51/255.0, green: 204/255.0, blue: 1, alpha: 1.0)
      case .darkGreen:
        return UIColor(red: 102/255.0, green: 204/255.0, blue: 0, alpha: 1.0)
      case .lightGreen:
        return UIColor(red: 102/255.0, green: 1, blue: 0, alpha: 1.0)
      case .brown:
        return UIColor(red: 160/255.0, green: 82/255.0, blue: 45/255.0, alpha: 1.0)
      case .orange:
        return UIColor(red: 1, green: 102/255.0, blue: 0, alpha: 1.0)
      case .yellow:
        return UIColor(red: 1, green: 1, blue: 0, alpha: 1.0)
      case .eraser:
        return .white
      }
    }
}

viewDidLoad代码

override func viewDidLoad() {
    super.viewDidLoad()
    
  
    let buttons = createColorButton()
    stackView.spacing = 5
    for button in buttons {
        stackView.addArrangedSubview(button)
                   button.layer.borderWidth = 1
                   button.layer.borderColor = UIColor.blue.cgColor
        
                   button.layer.cornerRadius = 10
            
        }
    view.addSubview(stackView)
    NSLayoutConstraint.activate([
        stackView.topAnchor.constraint(equalTo: view.topAnchor, constant: 200)
        ])
    
    setupImageViews()
    
}

1. 修复Tag与枚举初始化的不匹配问题 #

你在createColorButton中用pencilCase.hashValue设置按钮tag，但Pencil枚举的init?(tag:)方法里定义的tag是从1到11，而枚举默认的hashValue是从0开始的（第一个case的hashValue为0，第二个为1，以此类推）。这导致点击按钮时，Pencil(tag: sender.tag)会返回nil，直接进入guard分支返回，所以没有任何打印和逻辑执行。

修复方法二选一：

• 方法一：修改createColorButton的tag赋值逻辑，匹配枚举初始化的规则：

func createColorButton() -> [UIButton]{
    
    var buttons: [UIButton] = []
    for (index, pencilCase) in Pencil.allCases.enumerated() {
        let button = UIButton(type: .system)
        button.backgroundColor = pencilCase.color
        button.tag = index + 1 // 让tag从1开始，对应枚举init的定义
        button.addTarget(self, action: #selector(buttonClicked(_:)), for: .touchUpInside)
        // 给按钮添加固定大小约束，替代frame
        button.widthAnchor.constraint(equalToConstant: 100).isActive = true
        button.heightAnchor.constraint(equalToConstant: 100).isActive = true
        buttons.append(button)
    }
 return buttons
}

• 方法二：修改Pencil的init?(tag:)方法，适配枚举默认的hashValue：

init?(tag: Int) {
    switch tag {
    case 0:
      self = .black
    case 1:
      self = .grey
    case 2:
      self = .red
    case 3:
      self = .darkblue
    case 4:
      self = .lightBlue
    case 5:
      self = .darkGreen
    case 6:
      self = .lightGreen
    case 7:
      self = .brown
    case 8:
      self = .orange
    case 9:
      self = .yellow
    case 10:
      self = .eraser
    default:
      return nil
    }
}

2. 确保按钮交互状态正常 #

检查以下几点：

• 确认按钮的isUserInteractionEnabled为true（默认是true，若被意外设置为false会导致无法点击）
• 检查按钮是否被其他视图遮挡（比如stackView之外的视图覆盖在按钮上方）
• 确认stackView的isUserInteractionEnabled为true（默认是true）

3. 修复AutoLayout冲突问题 #

创建按钮时不要手动设置frame，因为之后会将按钮添加到使用AutoLayout的stackView中，手动设置frame可能导致按钮实际可点击区域异常。改用约束来定义按钮大小，如上述修复方法中的代码所示。

内容的提问来源于stack exchange，提问作者willd