将渐变层添加到具有相同名称Xcode / Swift的所有按钮

Question

Xcode / Swift是新的，我在我的应用程序中的不同View Controllers中为一堆按钮添加了渐变层。我想知道是否有一种方法可以同时定位具有特定名称的所有按钮，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，使您的UIButton以某种方式使用Gradient

适用于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)
    }
}

适用于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)
    }
}

然后在检查器for按钮中，您可以将Class设置为GradientButton检查图像

通过这种方式，您无需为渐变按钮编写代码。