用 Swift 5 创建多色单个字母（字符）

Question

我需要创建彩色字符串，其中每个字母都应具有多色/彩虹色。请参阅所附图片以便更好地理解。这需要使用 Swift 5+ (UIKit) 编码为 iOS 应用程序的仪表板创建。

在网络上，多色字符串有多种解决方案，但字符串的每个字母仅包含单一颜色，因此它们不符合我的目的。必须感谢任何建议。

multicolored letter/character prototype

Answer 1

步骤是：制作一个CAGradientLayer，然后：

view.layer.addSublayer(gradient)
view.addSubview(label)
view.mask = label

Answer 2

class LoginViewController: UIViewController {
    
    lazy var gradientBG:GradientBg = {
        let bg = GradientBg()
        return bg
    }()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .white
        gradientBG.frame = view.frame
        view.addSubview(gradientBG)
        
        let label = UILabel(frame: view.bounds)
        label.text = "Hello World"
        label.font = UIFont.boldSystemFont(ofSize: 30)
        label.textAlignment = .center
        gradientBG.addSubview(label)
        gradientBG.mask = label
    }
}

class GradientBg:UIView {
    
    override func layoutSubviews() {
        super.layoutSubviews()
        
        // Create a gradient layer
        let gradient = CAGradientLayer()

        // gradient colors in order which they will visually appear
        gradient.colors = [UIColor.red.cgColor, UIColor.blue.cgColor]

        // Gradient from left to right
        gradient.startPoint = CGPoint(x: 0.0, y: 0.5)
        gradient.endPoint = CGPoint(x: 1.0, y: 0.5)

        // set the gradient layer to the same size as the view
        gradient.frame = bounds
        // add the gradient layer to the views layer for rendering
        self.layer.addSublayer(gradient)
        
        // Create a label and add it as a subview
    }
}

Answer 3

在 Zeeshan Ahmed 和 Shadowrun 的帮助下，我解决了我的问题。我的最终解决方案是，

override func viewDidLoad() {
        super.viewDidLoad()
            
        let gradient = CAGradientLayer()
        gradient.colors = [UIColor.red.cgColor, UIColor.green.cgColor, UIColor.blue.cgColor]
        gradient.startPoint = CGPoint(x: 0, y: 0)
        gradient.endPoint = CGPoint(x: 0, y: 1)
            
        // bgView is a custom view with 100X100 sized
        gradient.frame = bgView.bounds
        bgView.layer.addSublayer(gradient)
        
        let label = UILabel(frame: bgView.bounds)
        label.text = "8"
        label.font = UIFont.boldSystemFont(ofSize: 90)
        label.textAlignment = .center
            
        bgView.addSubview(label)
        bgView.mask = label
   }

预期的输出应该是， Gradient single letter

感谢大家。

用 Swift 5 创建多色单个字母（字符）

Create multicolor single letter (character) with Swift 5

string

colors

uikit

ios

swift