SwiftUI：颜色-iOS 14 / macOS 10.16

Question

如何在Swift中获得给定UIColor的不同更亮和更暗的变体？

Answer 1

更新

在 UIColor Extension：

下方使用

extension UIColor {

    func lighter(by percentage: CGFloat = 30.0) -> UIColor? {
        return self.adjust(by: abs(percentage) )
    }

    func darker(by percentage: CGFloat = 30.0) -> UIColor? {
        return self.adjust(by: -1 * abs(percentage) )
    }

    func adjust(by percentage: CGFloat = 30.0) -> UIColor? {
        var red: CGFloat = 0, green: CGFloat = 0, blue: CGFloat = 0, alpha: CGFloat = 0
        if self.getRed(&red, green: &green, blue: &blue, alpha: &alpha) {
            return UIColor(red: min(red + percentage/100, 1.0),
                           green: min(green + percentage/100, 1.0),
                           blue: min(blue + percentage/100, 1.0),
                           alpha: alpha)
        } else {
            return nil
        }
    }
}

<强>用法：

let color = UIColor(red:0.96, green:0.54, blue:0.10, alpha:1.0)
color.lighter(30) // returns lighter color by 30%
color.darker(30) // returns darker color by 30%

而不是.lighter()和.darker()，您可以使用.adjust()为亮度为正值，为变暗使用负值

color.adjust(-30) // 30% darker color
color.adjust(30) // 30% lighter color

<强>输出：

Answer 2

SwiftUI：颜色-iOS 14 / macOS 10.16

extension Color {
    public func lighter(by amount: CGFloat = 0.2) -> Self { Self(UIColor(self).lighter(by: amount)) }
    public func darker(by amount: CGFloat = 0.2) -> Self { Self(UIColor(self).darker(by: amount)) }
}

_{要求针对iOS或（和）macOS的以下一项（或两项）}

AppKit：NSColor

extension NSColor {
    func mix(with color: NSColor, amount: CGFloat) -> Self {
        var red1: CGFloat = 0
        var green1: CGFloat = 0
        var blue1: CGFloat = 0
        var alpha1: CGFloat = 0

        var red2: CGFloat = 0
        var green2: CGFloat = 0
        var blue2: CGFloat = 0
        var alpha2: CGFloat = 0

        getRed(&red1, green: &green1, blue: &blue1, alpha: &alpha1)
        color.getRed(&red2, green: &green2, blue: &blue2, alpha: &alpha2)

        return Self(
            red: red1 * CGFloat(1.0 - amount) + red2 * amount,
            green: green1 * CGFloat(1.0 - amount) + green2 * amount,
            blue: blue1 * CGFloat(1.0 - amount) + blue2 * amount,
            alpha: alpha1
        )
    }

    func lighter(by amount: CGFloat = 0.2) -> Self { mix(with: .white, amount: amount) }
    func darker(by amount: CGFloat = 0.2) -> Self { mix(with: .black, amount: amount) }
}

UIKit：UIColor

extension UIColor {
    func mix(with color: UIColor, amount: CGFloat) -> Self {
        var red1: CGFloat = 0
        var green1: CGFloat = 0
        var blue1: CGFloat = 0
        var alpha1: CGFloat = 0

        var red2: CGFloat = 0
        var green2: CGFloat = 0
        var blue2: CGFloat = 0
        var alpha2: CGFloat = 0

        getRed(&red1, green: &green1, blue: &blue1, alpha: &alpha1)
        color.getRed(&red2, green: &green2, blue: &blue2, alpha: &alpha2)

        return Self(
            red: red1 * CGFloat(1.0 - amount) + red2 * amount,
            green: green1 * CGFloat(1.0 - amount) + green2 * amount,
            blue: blue1 * CGFloat(1.0 - amount) + blue2 * amount,
            alpha: alpha1
        )
    }

    func lighter(by amount: CGFloat = 0.2) -> Self { mix(with: .white, amount: amount) }
    func darker(by amount: CGFloat = 0.2) -> Self { mix(with: .black, amount: amount) }
}

Answer 3

要保存任何人的输入，简单实用的版本就是

<0,255>

使用方式

extension UIColor {

    var darker: UIColor {

    var h: CGFloat = 0, s: CGFloat = 0, b: CGFloat = 0, a: CGFloat = 0

        guard self.getHue(&h, saturation: &s, brightness: &b, alpha: &a) else {
            print("** some problem demuxing the color")
            return .gray
        }

        let nudged = b * 0.5

        return UIColor(hue: h, saturation: s, brightness: nudged, alpha: a)
    }
}

或

something.color = .yellow.darker

在大型项目中.......................

您绝对应该扩展Apple的模式：

backgroundColor = backgroundColor.darker

所以，有：

.withAlphaComponent(_ alpha: CGFloat)

明显

.withBrightnessComponent(_ alpha: CGFloat)

和/或

.withBrightnessComponentAdjustedBy(percentage: CGFloat)

Answer 4

Kenji-Tran的答案很好，只要你的起始颜色不是黑色（亮度值0）。通过添加几行额外代码，您还可以制作黑色＆＃34;更轻的＆＃34; （即将其变亮为灰度或颜色值）。

注意：我无法使用编辑添加此更改，因此我不能评论Kenji-Tran的回答＃＆＃ 34;新男孩＆＃34;代表，因此我没有找到其他方式来分享我对SO的了解，然后发布一个新答案。我希望没关系。

extension UIColor {
  /**
   Create a ligher color
   */
  func lighter(by percentage: CGFloat = 30.0) -> UIColor {
    return self.adjustBrightness(by: abs(percentage))
  }

  /**
   Create a darker color
   */
  func darker(by percentage: CGFloat = 30.0) -> UIColor {
    return self.adjustBrightness(by: -abs(percentage))
  }

  /**
   Try to increase brightness or decrease saturation
   */
  func adjustBrightness(by percentage: CGFloat = 30.0) -> UIColor {
    var h: CGFloat = 0, s: CGFloat = 0, b: CGFloat = 0, a: CGFloat = 0
    if self.getHue(&h, saturation: &s, brightness: &b, alpha: &a) {
      if b < 1.0 {
        /**
         Below is the new part, which makes the code work with black as well as colors
        */
        let newB: CGFloat
        if b == 0.0 {
            newB = max(min(b + percentage/100, 1.0), 0.0)
        } else {
            newB = max(min(b + (percentage/100.0)*b, 1.0), 0,0)
        }
        return UIColor(hue: h, saturation: s, brightness: newB, alpha: a)
      } else {
        let newS: CGFloat = min(max(s - (percentage/100.0)*s, 0.0), 1.0)
        return UIColor(hue: h, saturation: newS, brightness: b, alpha: a)
      }
    }
    return self
  }
}

Answer 5

修改了RGB值的版本

我在这里添加了基于之前答案的简单UIColor扩展名。它对我来说非常适合。

以下演示：

颜色处理代码

public extension UIColor {

    /**
     Create a lighter color
     */
    public func lighter(by percentage: CGFloat = 30.0) -> UIColor {
        return self.adjustBrightness(by: abs(percentage))
    }

    /**
     Create a darker color
     */
    public func darker(by percentage: CGFloat = 30.0) -> UIColor {
        return self.adjustBrightness(by: -abs(percentage))
    }

    /**
     Changing R, G, B values
     */

    func adjustBrightness(by percentage: CGFloat = 30.0) -> UIColor {

        var red: CGFloat = 0.0
        var green: CGFloat = 0.0
        var blue: CGFloat = 0.0
        var alpha: CGFloat = 0.0

        if self.getRed(&red, green: &green, blue: &blue, alpha: &alpha) {

            let pFactor = (100.0 + percentage) / 100.0

            let newRed = (red*pFactor).clamped(to: 0.0 ... 1.0)
            let newGreen = (green*pFactor).clamped(to: 0.0 ... 1.0)
            let newBlue = (blue*pFactor).clamped(to: 0.0 ... 1.0)

            return UIColor(red: newRed, green: newGreen, blue: newBlue, alpha: alpha)
        }

        return self
    }
}

限制功能 扩展可轻松保持最小值和最大值之间的值

extension Comparable {

    func clamped(to range: ClosedRange<Self>) -> Self {

        if self > range.upperBound {
            return range.upperBound
        } else if self < range.lowerBound {
            return range.lowerBound
        } else {
            return self
        }
    }
}

Answer 6

由于我在当前项目中使用SwiftUI，因此我改编了Stephen的最佳答案。经过Xcode 12.0，SwiftUI 2和iOS 14.0的测试

extension Color {
    var components: (red: CGFloat, green: CGFloat, blue: CGFloat, opacity: CGFloat) {
        #if canImport(UIKit)
        typealias NativeColor = UIColor
        #elseif canImport(AppKit)
        typealias NativeColor = NSColor
        #endif

        var r: CGFloat = 0
        var g: CGFloat = 0
        var b: CGFloat = 0
        var o: CGFloat = 0

        guard NativeColor(self).getRed(&r, green: &g, blue: &b, alpha: &o) else {
            return (0, 0, 0, 0)
        }
        return (r, g, b, o)
    }
    
    func lighter(by percentage: CGFloat = 30.0) -> Color {
        return self.adjust(by: abs(percentage) )
    }

    func darker(by percentage: CGFloat = 30.0) -> Color {
        return self.adjust(by: -1 * abs(percentage) )
    }

    func adjust(by percentage: CGFloat = 30.0) -> Color {
        return Color(red: min(Double(self.components.red + percentage/100), 1.0),
                     green: min(Double(self.components.green + percentage/100), 1.0),
                     blue: min(Double(self.components.blue + percentage/100), 1.0),
                     opacity: Double(self.components.opacity))
    }
}

Answer 7

在iOS 12的Swift 4.x的Xcode 10中进行了测试

以您的颜色作为UIColor并选择一个变暗的因子（作为CGFloat）

let baseColor = UIColor.red
let darkenFactor: CGFloat = 2

类型CGColor具有可选值components，该值将颜色分解为RGBA（作为CGFloat数组，其值在0到1之间）。然后，您可以使用从CGColor中获取的RGBA值来重建UIColor并对其进行操作。

let darkenedBase = UIColor(displayP3Red: startColor.cgColor.components![0] / darkenFactor, green: startColor.cgColor.components![1] / darkenFactor, blue: startColor.cgColor.components![2] / darkenFactor, alpha: 1)

在此示例中，每个RGB值均被2除以使颜色变暗为以前的一半。 Alpha值保持不变，但是您也可以在Alpha值而不是RGB上应用变暗因子。

Answer 8

使用lukszar钳位函数，我使用RGB值的实际比例为UIColor扩展编写了此函数。希望对您有帮助

public extension UIColor {

  public func lighter(by percentage: CGFloat = 30.0) -> UIColor {
    return self.adjustBrightness(by: abs(percentage))
  }

  public func darker(by percentage: CGFloat = 30.0) -> UIColor {
    return self.adjustBrightness(by: -abs(percentage))
  }

  func adjustBrightness(by percentage: CGFloat = 30.0) -> UIColor {

    let ratio = percentage/100

    var red:   CGFloat = 0.0
    var green: CGFloat = 0.0
    var blue:  CGFloat = 0.0
    var alpha: CGFloat = 0.0

    if self.getRed(&red, green: &green, blue: &blue, alpha: &alpha) {
      let newRed =   (red   + ((ratio < 0) ? red   * ratio : (1 - red)   * ratio)).clamped(to: 0.0 ... 1.0)
      let newGreen = (green + ((ratio < 0) ? green * ratio : (1 - green) * ratio)).clamped(to: 0.0 ... 1.0)
      let newBlue =  (blue  + ((ratio < 0) ? blue  * ratio : (1 - blue)  * ratio)).clamped(to: 0.0 ... 1.0)
      return UIColor(red: newRed, green: newGreen, blue: newBlue, alpha: alpha)
    }
    return self
  }
}

Answer 9

支持RGBA，HSBA和WB（灰度）的Swift 4版本

这是TranQuan的answer的变体，它还支持.white和.black等灰度颜色。（注意：我删除了饱和度调整，因为它不属于这样的简单函数。）

extension UIColor {
    /**
     Create a ligher color
     */
    func lighter(by percentage: CGFloat = 10.0) -> UIColor {
        return self.adjustBrightness(by: abs(percentage))
    }

    /**
     Create a darker color
     */
    func darker(by percentage: CGFloat = 10.0) -> UIColor {
        return self.adjustBrightness(by: -abs(percentage))
    }

    /**
     Try to adjust brightness and falls back to adjusting colors if necessary
     */
    func adjustBrightness(by percentage: CGFloat) -> UIColor {
        var alpha, hue, saturation, brightness, red, green, blue, white : CGFloat
        (alpha, hue, saturation, brightness, red, green, blue, white) = (0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0)

        let multiplier = percentage / 100.0

        if self.getHue(&hue, saturation: &saturation, brightness: &brightness, alpha: &alpha) {
            let newBrightness: CGFloat = max(min(brightness + multiplier*brightness, 1.0), 0.0)
            return UIColor(hue: hue, saturation: saturation, brightness: newBrightness, alpha: alpha)
        }
        else if self.getRed(&red, green: &green, blue: &blue, alpha: &alpha) {
            let newRed: CGFloat = min(max(red + multiplier*red, 0.0), 1.0)
            let newGreen: CGFloat = min(max(green + multiplier*green, 0.0), 1.0)
            let newBlue: CGFloat = min(max(blue + multiplier*blue, 0.0), 1.0)
            return UIColor(red: newRed, green: newGreen, blue: newBlue, alpha: alpha)
        }
        else if self.getWhite(&white, alpha: &alpha) {
            let newWhite: CGFloat = (white + multiplier*white)
            return UIColor(white: newWhite, alpha: alpha)
        }

        return self
    }
}

Answer 10

对于Swift 5.0：

extension UIColor {

func lighter(by percentage: CGFloat = 10.0) -> UIColor {
    return self.adjust(by: abs(percentage))
}

func darker(by percentage: CGFloat = 10.0) -> UIColor {
    return self.adjust(by: -abs(percentage))
}

func adjust(by percentage: CGFloat) -> UIColor {
    var alpha, hue, saturation, brightness, red, green, blue, white : CGFloat
    (alpha, hue, saturation, brightness, red, green, blue, white) = (0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0)

    let multiplier = percentage / 100.0

    if self.getHue(&hue, saturation: &saturation, brightness: &brightness, alpha: &alpha) {
        let newBrightness: CGFloat = max(min(brightness + multiplier*brightness, 1.0), 0.0)
        return UIColor(hue: hue, saturation: saturation, brightness: newBrightness, alpha: alpha)
    }
    else if self.getRed(&red, green: &green, blue: &blue, alpha: &alpha) {
        let newRed: CGFloat = min(max(red + multiplier*red, 0.0), 1.0)
        let newGreen: CGFloat = min(max(green + multiplier*green, 0.0), 1.0)
        let newBlue: CGFloat = min(max(blue + multiplier*blue, 0.0), 1.0)
        return UIColor(red: newRed, green: newGreen, blue: newBlue, alpha: alpha)
    }
    else if self.getWhite(&white, alpha: &alpha) {
        let newWhite: CGFloat = (white + multiplier*white)
        return UIColor(white: newWhite, alpha: alpha)
    }

    return self
    }
}

Answer 11

下面的代码示例演示如何获得给定颜色的浅色和深色，这在具有动态主题的应用程序中很有用

用于深色

+ (UIColor *)darkerColorForColor:(UIColor *)c
{
CGFloat r, g, b, a;
    if ([c getRed:&r green:&g blue:&b alpha:&a])
return [UIColor colorWithRed:MAX(r - 0.2, 0.0)
                               green:MAX(g - 0.2, 0.0)
                                blue:MAX(b - 0.2, 0.0)
return nil; 
}

浅色

+ (UIColor *)lighterColorForColor:(UIColor *)c
{
CGFloat r, g, b, a;
    if ([c getRed:&r green:&g blue:&b alpha:&a])
return [UIColor colorWithRed:MIN(r + 0.2, 1.0)
                       green:MIN(g + 0.2, 1.0)
                        blue:MIN(b + 0.2, 1.0)
alpha:a];
return nil;
}

为给定的UIColor获得更浅和更暗的颜色变化

11 个答案:

更新

SwiftUI：颜色-iOS 14 / macOS 10.16

AppKit：NSColor

UIKit：UIColor

在大型项目中.......................