为给定的 UIColor 获取更亮和更暗的颜色变化

Question

如何在 Swift 中获得给定 UIColor 的不同亮色和暗色变化？

Answer 1

已更新

使用下面的 UIColor Extension:

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
        }
    }
}

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()，正值表示变亮，负值表示变暗

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

输出：

Answer 2

我想提供另一个使用亮度和饱和度而不是 RGB 的版本

extension UIColor {
  /**
   Create a lighter 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 {
        let newB: CGFloat = 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 3

Kenji-Tran 的回答很好，只要您的起始颜色不是黑色（亮度值 0）。通过添加几行额外的代码，您还可以使黑色 "lighter"（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，并且由于我的 "new boy" 不允许我对 Kenji-Tran 的回答发表评论代表，因此我发现没有其他方法可以通过发布新答案来分享我对 SO 的了解。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 4

修改RGB值的版本

我在这里放置了简单的 UIColor 扩展，它基于以前的答案。它非常适合我。

下面的演示：

颜色操作代码

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
    }
}

钳位函数 扩展以轻松将值保持在最小值和最大值之间。

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 5

使用 lukszar clampled 函数，我为 UIColor 扩展编写了这个函数，使用了 RGB 值的实际比例。希望对你有帮助

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 6

Swift 4版本支持RGBA、HSBA、WB（灰度）

这是 TranQuan 的的变体，它也支持 .white 和 .black 等灰度颜色。（注意：我删除了饱和度调整，因为我认为它不属于这样一个简单的功能。）

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 7

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 8

为了省人打字，简单实用的版本就是

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)
    }
}

喜欢

something.color = .yellow.darker

或

backgroundColor = backgroundColor.darker

在一个大项目上 .....................

你绝对应该扩展 Apple 的模式：

.withAlphaComponent(_ alpha: CGFloat)

所以，有：

.withBrightnessComponent(_ alpha: CGFloat)

而且明显

.withBrightnessComponentAdjustedBy(percentage: CGFloat)

and/or

.withBrightnessComponentMultipliedBy(factor: CGFloat)

Answer 9

下面的代码示例演示了如何获得给定颜色的更浅和更深的阴影，这在具有动态主题的应用程序中很有用

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;
}

Answer 10

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)) }
}

_{iOS 或（和）macOS}

需要以下一项（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 11

由于我在当前项目中使用 SwiftUI，因此我采用了 Stephen 的最佳答案。使用 Xcode 12.0、SwiftUI 2 和 iOS 14.0

进行测试

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 12

对于 macOS 个应用程序，有一个内置的颜色混合功能。

要使颜色变浅，只需调用

NSColor.systemRed.blended(withFraction: 0.35, of: .white)

Answer 13

我正在使用 SwiftUI 并正在寻找快速解决方案。

此方法更改 alpha 通道（0 是透明的，1 是不透明的）并将其放在白色视图前面，因此您实际上是在将白色与颜色混合。更高的 alpha 值，更多的白色混合 = 更亮。

将 Color 转换为 UIColor，修改并转换回来完成工作：

Color(UIColor(Color.blue).withAlphaComponent(0.5))
    .background(Color.white) // IMPORTANT: otherwise your view will be see-through

要加深颜色，请将 Color.white 更改为 Color.black

为给定的 UIColor 获取更亮和更暗的颜色变化

Get lighter and darker color variations for a given UIColor

core-graphics

colors

uicolor

ios

swift

已更新

在一个大项目上 .....................

SwiftUI：颜色 - iOS 14 / macOS 10.16

AppKit：NSColor

UIKit: UIColor