Question

我创建了一个UIButton子类来为一批按钮添加渐变层，我想知道是否有办法设置按钮的高度，因为它们都是相同的高度。这是我的渐变图层代码，所以我想知道它是否可能以及我需要在代码中放置它的位置：

public class GradientButton: UIButton {

override public func layoutSubviews() {
    super.layoutSubviews()
    createGradientBackground()

}  
 func createGradientBackground() {

    let gradientLayer = CAGradientLayer()
    gradientLayer.frame = self.layer.bounds

    let color1 = UIColor(red:0.05, green:0.29, blue:0.49, alpha:1.0).CGColor as CGColorRef
    let color2 = UIColor(red:0.08, green:0.23, blue:0.39, alpha:1.0).CGColor as CGColorRef

    gradientLayer.colors = [color1, color2]

    gradientLayer.locations = [0.0, 1.0]

    self.layer.insertSublayer(gradientLayer, atIndex: 0)
    }
}

Answer 1

当然，只需添加：

init() {
    self.frame.size.height = 50.0
    //Do other stuff you may want
}

OR：

func createGradientBackground() {

    let gradientLayer = CAGradientLayer()
    gradientLayer.frame = self.layer.bounds

    let color1 = UIColor(red:0.05, green:0.29, blue:0.49, alpha:1.0).CGColor as CGColorRef
    let color2 = UIColor(red:0.08, green:0.23, blue:0.39, alpha:1.0).CGColor as CGColorRef

    gradientLayer.colors = [color1, color2]

    gradientLayer.locations = [0.0, 1.0]

    self.layer.insertSublayer(gradientLayer, atIndex: 0)

    //set custom height wanted 
    self.frame.size.height = 50.0
}

您可以在自定义init（）或createGradientBackground（）内部执行此操作。但是，您必须记住在故事板中对按钮设置的约束。

Answer 2

最简单的方法是覆盖var intrinsicContentSize: CGSize。

示例：

open class AMPrimaryButton: UIButton {
    
    open override var intrinsicContentSize: CGSize {
        var size = super.intrinsicContentSize
        size.height = 50
        return size
    }
}

Answer 3

如果按钮具有自动布局，则可以按以下方式更新约束运行时：

import UIKit

class CustomButton: UIButton {

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        setupConstraints()
    }

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

    func setupConstraints() {
        NSLayoutConstraint.activate([
            self.heightAnchor.constraint(equalToConstant: 50)
        ])
    }

    override class var requiresConstraintBasedLayout: Bool {
        return true
    }
}

在这里您必须设置requiresConstraintBasedLayout。

如果自定义视图无法使用自动调整大小正确地布局，则应覆盖此属性以返回true。

来自Apple Documentation

希望它对您有帮助。

UIButton子类设置按钮Xcode / Swift的高度

3 个答案: