将渐变层添加到具有相同名称 Xcode/Swift 的所有按钮

Question

对于 Xcode/Swift 来说太新了，我正在为我的应用程序中不同视图控制器中的一堆按钮添加一个渐变层。我想知道是否有一种方法可以一次将所有具有特定名称的按钮作为目标，而不是将我的代码单独添加到每个页面中。这是我的渐变代码：

let gradientLayer = CAGradientLayer()
gradientLayer.frame = self.btnSavePhoto.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.btnSavePhoto.layer.addSublayer(gradientLayer)

Answer 1

您可以创建一个自定义类，以某种方式使用 Gradient 创建您的 UIButton

对于 Swift 3

import UIKit

public class GradientButton: UIButton {

    override public func layoutSubviews() {
        super.layoutSubviews()
        layoutGradientButtonLayer()
    }

    // MARK: Private
    private func layoutGradientButtonLayer() {
        let gradientLayer = CAGradientLayer()
        let color1 = UIColor(red:0.05, green:0.29, blue:0.49, alpha: 1.0).cgColor as CGColor
        let color2 = UIColor(red:0.08, green:0.23, blue:0.39, alpha: 1.0).cgColor as CGColor
        gradientLayer.colors = [color1, color2]
        gradientLayer.locations = [0.0, 1.0]
        self.layer.addSublayer(gradientLayer)
    }
}

对于 Swift 2.3

import UIKit

public class GradientButton: UIButton {

    override public func layoutSubviews() {
        super.layoutSubviews()
        layoutGradientButtonLayer()
    }

    // MARK: Private
    private func layoutGradientButtonLayer() {
         let gradientLayer = CAGradientLayer()
         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.addSublayer(gradientLayer)
    }
}

然后在按钮的检查器中，您可以将 Class 设置为 GradientButton 检查图像

这样你就不需要为你的渐变按钮编写代码了。