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%
Note: 我不是't able to add this change using an Edit and I' m不允许评论Kenji-Tran 's answer due to my 3025048 rep, therefore I found no other way to share my knowledge on SO then by posting a new answer. I hope that'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
}
}
2
Version with RGB values modification
这里我把简单的 UIColor 扩展名基于之前的答案 . 它对我来说非常合适 .
下面演示：
Colors manipulation code
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
}
}
6 回答
更新
使用以下 UIColor Extension:
Usage:
而不是
.lighter()和.darker()，您可以使用.adjust()，其中正值用于闪电，负值用于变暗Output:
我想提供另一个使用亮度和饱和度而不是RGB的版本
Kenji-Tran的答案很好，只要您的起始颜色不是黑色（亮度值0） . 通过添加几行额外代码，您还可以使黑色“更亮”（即将其变亮为灰度或颜色值） .
Note: 我不是't able to add this change using an Edit and I' m不允许评论Kenji-Tran 's answer due to my 3025048 rep, therefore I found no other way to share my knowledge on SO then by posting a new answer. I hope that'没关系 .
Version with RGB values modification
这里我把简单的
UIColor扩展名基于之前的答案 . 它对我来说非常合适 .下面演示：
Colors manipulation code
Clamped function 扩展可轻松保持最小值和最大值之间的值 .
Tested in Xcode 10 with Swift 4.x for iOS 12
从你的颜色开始作为UIColor并选择一个变暗因子（作为CGFloat）
CGColor类型具有可选值
components，它将颜色分解为RGBA（作为CGFloat数组，其值介于0和1之间） . 然后，您可以使用从CGColor中获取的RGBA值重建UIColor并对其进行操作 .在这个例子中，每个RGB值被除以2，使得颜色一半变暗 . alpha值保持不变，但您可以选择将暗因子应用于alpha值而不是RGB .
使用lukszar clampled函数，我使用实际比例的RGB值为UIColor扩展编写了这个函数 . 我希望它有所帮助