Question

我的项目中有几个格式相同的按钮。将相同格式应用于多个按钮的最佳方法是什么，所以我不必每次都手动执行此操作？

感谢您的帮助！

Answer 1

您可以继承UIButton并使用它。

这是UIButton子类的一些示例代码，以及以编程方式创建两个新按钮。如果您正在使用故事板，请在视图中添加UIButton，然后在Identity Inspector中将其类更改为自定义子类。

UIButton子类：

class OneButtonToRuleThemAll: UIButton {
    // This is used when you create your view programatically.
    override init(frame: CGRect) {
        super.init(frame: frame)
        commonInit()
    }

    // This is used when the view is created from a storyboard or a Nib file.
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        commonInit()
    }

    // This is optional.
    // You can use it to initialize your view programatically with specific parameters.
    convenience init(frame: CGRect, title: String) {
        self.init(frame: frame)
        setTitle(title, for: .normal)
    }

    // Do your custom configuration here
    func commonInit() {
        clipsToBounds = true
        let backgroundImage = UIImage(from: .green)
        setBackgroundImage(backgroundImage, for: .normal)
        setTitleColor(.white, for: .normal)
        titleLabel?.font = UIFont.boldSystemFont(ofSize: 16)
        contentEdgeInsets = UIEdgeInsets(top: 10, left: 20, bottom: 10, right: 20)
    }

    // You may need to perform some of your configurations outsite the initializers.
    // You can use other methods from the UIView lifecycle for this.
    override func layoutSubviews() {
        super.layoutSubviews()
        layer.cornerRadius = frame.height/2
    }
}

这对于此答案并不重要，但如果您想更改按钮的背景，则应使用UIImage而不是设置背景颜色，以便使用高光效果。此扩展可用于从UIColor创建图像：

extension UIImage {
    convenience init?(from color: UIColor, size: CGSize = CGSize(width: 1, height: 1)) {
        let rect = CGRect(origin: .zero, size: size)
        UIGraphicsBeginImageContextWithOptions(rect.size, false, 0.0)
        color.setFill()
        UIRectFill(rect)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        guard let cgImage = image?.cgImage else { return nil }
        self.init(cgImage: cgImage)
    }
}

以编程方式创建两个按钮：

@IBOutlet weak var buttonsStackView: UIStackView!

override func viewDidLoad() {
    super.viewDidLoad()

    // Using the designated initializer
    let button = OneButtonToRuleThemAll(frame: CGRect.zero)
    button.setTitle("Button From Code", for: .normal)
    buttonsStackView.addArrangedSubview(button)

    // Using the convenience initializer
    let button2 = OneButtonToRuleThemAll(frame: CGRect.zero, title: "But Wait, There's More!")
    buttonsStackView.addArrangedSubview(button2)
}

将相同的格式应用于按钮子集？

1 个答案: