UIButton 的渐变未显示

Posted 2023-03-10

【中文标题】UIButton 的渐变未显示

【英文标题】：Gradient of UIButton is not showing

【发布时间】：2019-08-25 00:44:18

【问题描述】：

我正在尝试在按钮上添加渐变，但它没有显示出来。所有其他按钮部分都可以正常工作并完美显示！

创建按钮的函数

private func createButtonMenu(buttonTitle: String, buttonIcon: UIImage, colorOne: UIColor, colorTwo: UIColor) -> UIButton

        let button = UIButton()
        button.setTitle(buttonTitle, for: .normal)
        button.translatesAutoresizingMaskIntoConstraints = false
        button.contentHorizontalAlignment = .leading
        button.contentVerticalAlignment = .bottom
        button.contentEdgeInsets = UIEdgeInsets(top: 0, left: 10, bottom: 10, right: 0)
        button.layer.cornerRadius = 30
        button.layer.masksToBounds = true

        let icon = UIImageView(image: buttonIcon)
        icon.translatesAutoresizingMaskIntoConstraints = false

        button.addSubview(icon)

        button.heightAnchor.constraint(equalToConstant: 100).isActive = true


        icon.topAnchor.constraint(equalTo: button.topAnchor, constant: 10).isActive = true
        icon.leadingAnchor.constraint(equalTo: button.leadingAnchor, constant: 10).isActive = true

        let gradientLayer = CAGradientLayer()
        gradientLayer.frame = button.bounds
        gradientLayer.colors = [UIColor.red, UIColor.blue]
        gradientLayer.locations = [0.0, 1.0]
        gradientLayer.startPoint = CGPoint(x: 0.0, y: 0.5)
        gradientLayer.endPoint = CGPoint(x: 1.0, y: 0.5)

        button.layer.insertSublayer(gradientLayer, at: 0)

        //button.backgroundColor = .red
        icon.widthAnchor.constraint(equalToConstant: 30).isActive = true
        icon.heightAnchor.constraint(equalToConstant: 30).isActive = true

        return button
    

在视图中插入按钮的函数

private func configuringButtons()
        //Creating buttons
        let userButtonMenu: UIButton = createButtonMenu(buttonTitle: "009", buttonIcon:  #imageLiteral(resourceName: "woman"), colorOne: .red, colorTwo: .blue)
        view.addSubview(userButtonMenu)

【问题讨论】：

没有工作克里斯，背景颜色按预期工作，但渐变没有

让button.addSubview(icon) 尝试button.imageView = icon

button.layer.insertSublayer(gradientLayer, at: 0) 你不认为它不应该是 0 但最重要的是我的意思是 totallayers.count

【参考方案1】：

渐变层中的颜色必须是 CGColor 类型，而不是 UIColor。

gradientLayer.colors = [UIColor.red.cgColor, UIColor.blue.cgColor]

【讨论】：

@VinniciusPereira 您是否遇到任何错误或只是无法正常工作？