ios 如何使用十六进制颜色值

How to use hex color values

提问by Stephen Fox

I am trying to use hex color values in Swift, instead of the few standard ones that UIColorallows you to use, but I have no idea how to do it.

我试图在 Swift 中使用十六进制颜色值，而不是UIColor允许您使用的少数标准颜色值，但我不知道该怎么做。

Example: how would I use #ffffffas a color?

示例：我将如何#ffffff用作颜色？

回答by Sulthan

#ffffffare actually 3 color components in hexadecimal notation - red ff, green ffand blue ff. You can write hexadecimal notation in Swift using 0xprefix, e.g 0xFF

#ffffff实际上是十六进制表示法中的 3 个颜色分量 - 红色ff、绿色ff和蓝色ff。您可以使用0x前缀在 Swift 中编写十六进制表示法，例如0xFF

To simplify the conversion, let's create an initializer that takes integer (0 - 255) values:

为了简化转换，让我们创建一个采用整数 (0 - 255) 值的初始化程序：

extension UIColor {
   convenience init(red: Int, green: Int, blue: Int) {
       assert(red >= 0 && red <= 255, "Invalid red component")
       assert(green >= 0 && green <= 255, "Invalid green component")
       assert(blue >= 0 && blue <= 255, "Invalid blue component")

       self.init(red: CGFloat(red) / 255.0, green: CGFloat(green) / 255.0, blue: CGFloat(blue) / 255.0, alpha: 1.0)
   }

   convenience init(rgb: Int) {
       self.init(
           red: (rgb >> 16) & 0xFF,
           green: (rgb >> 8) & 0xFF,
           blue: rgb & 0xFF
       )
   }
}

Usage:

用法：

let color = UIColor(red: 0xFF, green: 0xFF, blue: 0xFF)
let color2 = UIColor(rgb: 0xFFFFFF)

How to get alpha?

如何获得阿尔法？

Depending on your use case, you can simply use the native UIColor.withAlphaComponentmethod, e.g.

根据您的用例，您可以简单地使用本机UIColor.withAlphaComponent方法，例如

let semitransparentBlack = UIColor(rgb: 0x000000).withAlphaComponent(0.5)

Or you can add an additional (optional) parameter to the above methods:

或者您可以向上述方法添加一个额外的（可选）参数：

convenience init(red: Int, green: Int, blue: Int, a: CGFloat = 1.0) {
    self.init(
        red: CGFloat(red) / 255.0,
        green: CGFloat(green) / 255.0,
        blue: CGFloat(blue) / 255.0,
        alpha: a
    )
}

convenience init(rgb: Int, a: CGFloat = 1.0) {
    self.init(
        red: (rgb >> 16) & 0xFF,
        green: (rgb >> 8) & 0xFF,
        blue: rgb & 0xFF,
        a: a
    )
}

(we cannot name the parameter alphabecause of a name collision with the existing initializer).

（alpha由于与现有初始化程序的名称冲突，我们无法命名参数）。

Called as:

称为：

let color = UIColor(red: 0xFF, green: 0xFF, blue: 0xFF, a: 0.5)
let color2 = UIColor(rgb: 0xFFFFFF, a: 0.5)

To get the alpha as an integer 0-255, we can

要将 alpha 设为 0-255 的整数，我们可以

convenience init(red: Int, green: Int, blue: Int, a: Int = 0xFF) {
    self.init(
        red: CGFloat(red) / 255.0,
        green: CGFloat(green) / 255.0,
        blue: CGFloat(blue) / 255.0,
        alpha: CGFloat(a) / 255.0
    )
}

// let's suppose alpha is the first component (ARGB)
convenience init(argb: Int) {
    self.init(
        red: (argb >> 16) & 0xFF,
        green: (argb >> 8) & 0xFF,
        blue: argb & 0xFF,
        a: (argb >> 24) & 0xFF
    )
}

Called as

称为

let color = UIColor(red: 0xFF, green: 0xFF, blue: 0xFF, a: 0xFF)
let color2 = UIColor(argb: 0xFFFFFFFF)

Or a combination of the previous methods. There is absolutely no need to use strings.

或者之前方法的组合。绝对没有必要使用字符串。

回答by Ethan Strider

This is a function that takes a hex string and returns a UIColor.
(You can enter hex strings with either format: #ffffffor ffffff)

这是一个接受十六进制字符串并返回 UIColor 的函数。
（您可以使用以下任一格式输入十六进制字符串：#ffffff或ffffff）

Usage:

用法：

var color1 = hexStringToUIColor("#d3d3d3")

Swift 5:(Swift 4+)

斯威夫特 5：（斯威夫特 4+）

func hexStringToUIColor (hex:String) -> UIColor {
    var cString:String = hex.trimmingCharacters(in: .whitespacesAndNewlines).uppercased()

    if (cString.hasPrefix("#")) {
        cString.remove(at: cString.startIndex)
    }

    if ((cString.count) != 6) {
        return UIColor.gray
    }

    var rgbValue:UInt64 = 0
    Scanner(string: cString).scanHexInt64(&rgbValue)

    return UIColor(
        red: CGFloat((rgbValue & 0xFF0000) >> 16) / 255.0,
        green: CGFloat((rgbValue & 0x00FF00) >> 8) / 255.0,
        blue: CGFloat(rgbValue & 0x0000FF) / 255.0,
        alpha: CGFloat(1.0)
    )
}

Swift 3:

斯威夫特 3：

func hexStringToUIColor (hex:String) -> UIColor {
    var cString:String = hex.trimmingCharacters(in: .whitespacesAndNewlines).uppercased()

    if (cString.hasPrefix("#")) {
        cString.remove(at: cString.startIndex)
    }

    if ((cString.characters.count) != 6) {
        return UIColor.gray
    }

    var rgbValue:UInt32 = 0
    Scanner(string: cString).scanHexInt32(&rgbValue)

    return UIColor(
        red: CGFloat((rgbValue & 0xFF0000) >> 16) / 255.0,
        green: CGFloat((rgbValue & 0x00FF00) >> 8) / 255.0,
        blue: CGFloat(rgbValue & 0x0000FF) / 255.0,
        alpha: CGFloat(1.0)
    )
}

Swift 2:

斯威夫特 2：

func hexStringToUIColor (hex:String) -> UIColor {
    var cString:String = hex.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet() as NSCharacterSet).uppercaseString

    if (cString.hasPrefix("#")) {
      cString = cString.substringFromIndex(cString.startIndex.advancedBy(1))
    }

    if ((cString.characters.count) != 6) {
      return UIColor.grayColor()
    }

    var rgbValue:UInt32 = 0
    NSScanner(string: cString).scanHexInt(&rgbValue)

    return UIColor(
        red: CGFloat((rgbValue & 0xFF0000) >> 16) / 255.0,
        green: CGFloat((rgbValue & 0x00FF00) >> 8) / 255.0,
        blue: CGFloat(rgbValue & 0x0000FF) / 255.0,
        alpha: CGFloat(1.0)
    )
}

---

---

Source: arshad/gist:de147c42d7b3063ef7bc

来源：arshad/gist：de147c42d7b3063ef7bc

Edit: Updated the code. Thanks, Hlung, jaytrixz, Ahmad F, Kegham K, and Adam Waite!

编辑：更新了代码。谢谢 Hlung、jaytrixz、Ahmad F、Kegham K 和 Adam Waite！

回答by Luca Torella

Swift 5 (Swift 4, Swift 3)UIColor extension:

Swift 5 (Swift 4, Swift 3)UIColor 扩展：

extension UIColor {
    convenience init(hexString: String) {
        let hex = hexString.trimmingCharacters(in: CharacterSet.alphanumerics.inverted)
        var int = UInt64()
        Scanner(string: hex).scanHexInt64(&int)
        let a, r, g, b: UInt64
        switch hex.count {
        case 3: // RGB (12-bit)
            (a, r, g, b) = (255, (int >> 8) * 17, (int >> 4 & 0xF) * 17, (int & 0xF) * 17)
        case 6: // RGB (24-bit)
            (a, r, g, b) = (255, int >> 16, int >> 8 & 0xFF, int & 0xFF)
        case 8: // ARGB (32-bit)
            (a, r, g, b) = (int >> 24, int >> 16 & 0xFF, int >> 8 & 0xFF, int & 0xFF)
        default:
            (a, r, g, b) = (255, 0, 0, 0)
        }
        self.init(red: CGFloat(r) / 255, green: CGFloat(g) / 255, blue: CGFloat(b) / 255, alpha: CGFloat(a) / 255)
    }
}

Usage:

用法：

let darkGrey = UIColor(hexString: "#757575")

Swift 2.xversion:

斯威夫特 2.x版本：

extension UIColor {
    convenience init(hexString: String) {
        let hex = hexString.stringByTrimmingCharactersInSet(NSCharacterSet.alphanumericCharacterSet().invertedSet)
        var int = UInt32()
        NSScanner(string: hex).scanHexInt(&int)
        let a, r, g, b: UInt32
        switch hex.characters.count {
        case 3: // RGB (12-bit)
            (a, r, g, b) = (255, (int >> 8) * 17, (int >> 4 & 0xF) * 17, (int & 0xF) * 17)
        case 6: // RGB (24-bit)
            (a, r, g, b) = (255, int >> 16, int >> 8 & 0xFF, int & 0xFF)
        case 8: // ARGB (32-bit)
            (a, r, g, b) = (int >> 24, int >> 16 & 0xFF, int >> 8 & 0xFF, int & 0xFF)
        default:
            (a, r, g, b) = (255, 0, 0, 0)
        }
        self.init(red: CGFloat(r) / 255, green: CGFloat(g) / 255, blue: CGFloat(b) / 255, alpha: CGFloat(a) / 255)
    }
}

回答by Rudolf Adamkovi?

UIColor:

UIColor：

extension UIColor {

    convenience init(hex: Int) {
        let components = (
            R: CGFloat((hex >> 16) & 0xff) / 255,
            G: CGFloat((hex >> 08) & 0xff) / 255,
            B: CGFloat((hex >> 00) & 0xff) / 255
        )
        self.init(red: components.R, green: components.G, blue: components.B, alpha: 1)
    }

}

CGColor:

CGColor：

extension CGColor {

    class func colorWithHex(hex: Int) -> CGColorRef {

        return UIColor(hex: hex).CGColor

    }

}

---

---

Usage

用法

let purple = UIColor(hex: 0xAB47BC)

回答by Eduardo

Swift 4: Combining the answers of Sulthan and Luca Torella :

Swift 4：结合 Sulthan 和 Luca Torella 的答案：

extension UIColor {
    convenience init(hexFromString:String, alpha:CGFloat = 1.0) {
        var cString:String = hexFromString.trimmingCharacters(in: .whitespacesAndNewlines).uppercased()
        var rgbValue:UInt32 = 10066329 //color #999999 if string has wrong format

        if (cString.hasPrefix("#")) {
            cString.remove(at: cString.startIndex)
        }

        if ((cString.count) == 6) {
            Scanner(string: cString).scanHexInt32(&rgbValue)
        }

        self.init(
            red: CGFloat((rgbValue & 0xFF0000) >> 16) / 255.0,
            green: CGFloat((rgbValue & 0x00FF00) >> 8) / 255.0,
            blue: CGFloat(rgbValue & 0x0000FF) / 255.0,
            alpha: alpha
        )
    }
}

Usage examples:

用法示例：

let myColor = UIColor(hexFromString: "4F9BF5")

let myColor = UIColor(hexFromString: "#4F9BF5")

let myColor = UIColor(hexFromString: "#4F9BF5", alpha: 0.5)

回答by Jorge Casariego

With Swift 2.0 and Xcode 7.0.1 you can create this function:

使用 Swift 2.0 和 Xcode 7.0.1，您可以创建此函数：

    // Creates a UIColor from a Hex string.
    func colorWithHexString (hex:String) -> UIColor {
        var cString:String = hex.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet()).uppercaseString

        if (cString.hasPrefix("#")) {
            cString = (cString as NSString).substringFromIndex(1)
        }

        if (cString.characters.count != 6) {
            return UIColor.grayColor()
        }

        let rString = (cString as NSString).substringToIndex(2)
        let gString = ((cString as NSString).substringFromIndex(2) as NSString).substringToIndex(2)
        let bString = ((cString as NSString).substringFromIndex(4) as NSString).substringToIndex(2)

        var r:CUnsignedInt = 0, g:CUnsignedInt = 0, b:CUnsignedInt = 0;
        NSScanner(string: rString).scanHexInt(&r)
        NSScanner(string: gString).scanHexInt(&g)
        NSScanner(string: bString).scanHexInt(&b)


        return UIColor(red: CGFloat(r) / 255.0, green: CGFloat(g) / 255.0, blue: CGFloat(b) / 255.0, alpha: CGFloat(1))
    }

and then use it in this way:

然后以这种方式使用它：

let color1 = colorWithHexString("#1F437C")

Updated For Swift 4

为 Swift 4 更新

func colorWithHexString (hex:String) -> UIColor {

    var cString = hex.trimmingCharacters(in: CharacterSet.whitespacesAndNewlines).uppercased()

    if (cString.hasPrefix("#")) {
        cString = (cString as NSString).substring(from: 1)
    }

    if (cString.characters.count != 6) {
        return UIColor.gray
    }

    let rString = (cString as NSString).substring(to: 2)
    let gString = ((cString as NSString).substring(from: 2) as NSString).substring(to: 2)
    let bString = ((cString as NSString).substring(from: 4) as NSString).substring(to: 2)

    var r:CUnsignedInt = 0, g:CUnsignedInt = 0, b:CUnsignedInt = 0;
    Scanner(string: rString).scanHexInt32(&r)
    Scanner(string: gString).scanHexInt32(&g)
    Scanner(string: bString).scanHexInt32(&b)


    return UIColor(red: CGFloat(r) / 255.0, green: CGFloat(g) / 255.0, blue: CGFloat(b) / 255.0, alpha: CGFloat(1))
}

回答by Norman

Swift 5.1: Hex and CSS color name support via a UIColor

Swift 5.1：通过 UIColor 支持十六进制和 CSS 颜色名称

Gist code

要点代码

Swift Package

迅捷包

Example strings:

示例字符串：

• Orange, Lime, Tomato, etc.
• Clear, Transparent, nil, and empty string yield [UIColor clearColor]
• abc
• abc7
• #abc7
• 00FFFF
• #00FFFF
• 00FFFF77

• Orange，Lime，Tomato，等。
• Clear, Transparent, nil, 和空字符串产量[UIColor clearColor]
• abc
• abc7
• #abc7
• 00FFFF
• #00FFFF
• 00FFFF77

Playground output:

游乐场输出：

回答by puneeth

The simplest way to add color programmatically is by using ColorLiteral.

以编程方式添加颜色的最简单方法是使用ColorLiteral。

Just add the property ColorLiteral as shown in the example, Xcode will prompt you with a whole list of colors which you can choose. The advantage of doing so is lesser code, add HEX values or RGB. You will also get the recently used colors from the storyboard.

只需添加属性 ColorLiteral 如示例中所示，Xcode 将提示您完整的颜色列表供您选择。这样做的好处是代码更少，添加 HEX 值或 RGB。您还将从故事板中获取最近使用的颜色。

Example:self.view.backgroundColor = ColorLiteral

示例：self.view.backgroundColor = ColorLiteral

回答by Raniys

Warning "'scanHexInt32' was deprecated in iOS 13.0" was fixed.

警告“'scanHexInt32' 已在 iOS 13.0 中被弃用”已修复。

The sample should work on Swift2.2 and above(Swift2.x, Swift3.x, Swift4.x, Swift5.x):

该示例应该适用于 Swift2.2 及更高版本（Swift2.x、Swift3.x、Swift4.x、Swift5.x）：

extension UIColor {

    // hex sample: 0xf43737
    convenience init(_ hex: Int, alpha: Double = 1.0) {
        self.init(red: CGFloat((hex >> 16) & 0xFF) / 255.0, green: CGFloat((hex >> 8) & 0xFF) / 255.0, blue: CGFloat((hex) & 0xFF) / 255.0, alpha: CGFloat(255 * alpha) / 255)
    }

    convenience init(_ hexString: String, alpha: Double = 1.0) {
        let hex = hexString.trimmingCharacters(in: CharacterSet.alphanumerics.inverted)
        var int = UInt64()
        Scanner(string: hex).scanHexInt64(&int)

        let r, g, b: UInt64
        switch hex.count {
        case 3: // RGB (12-bit)
            (r, g, b) = ((int >> 8) * 17, (int >> 4 & 0xF) * 17, (int & 0xF) * 17)
        case 6: // RGB (24-bit)
            (r, g, b) = (int >> 16, int >> 8 & 0xFF, int & 0xFF)
        default:
            (r, g, b) = (1, 1, 0)
        }

        self.init(red: CGFloat(r) / 255, green: CGFloat(g) / 255, blue: CGFloat(b) / 255, alpha: CGFloat(255 * alpha) / 255)
    }

    convenience init(r: CGFloat, g: CGFloat, b: CGFloat, a: CGFloat = 1) {
        self.init(red: (r / 255), green: (g / 255), blue: (b / 255), alpha: a)
    }
}

Use them like below:

像下面这样使用它们：

UIColor(0xF54A45)
UIColor(0xF54A45, alpha: 0.7)
UIColor("#f44")
UIColor("#f44", alpha: 0.7)
UIColor("#F54A45")
UIColor("#F54A45", alpha: 0.7)
UIColor("F54A45")
UIColor("F54A45", alpha: 0.7)
UIColor(r: 245.0, g: 73, b: 69)
UIColor(r: 245.0, g: 73, b: 69, a: 0.7)

回答by Grimxn

Thisanswer shows how to do it in Obj-C. The bridge is to use

这个答案显示了如何在 Obj-C 中做到这一点。桥是用

let rgbValue = 0xFFEEDD
let r = Float((rgbValue & 0xFF0000) >> 16)/255.0
let g = Float((rgbValue & 0xFF00) >> 8)/255.0
let b = Float((rgbValue & 0xFF))/255.0
self.backgroundColor = UIColor(red:r, green: g, blue: b, alpha: 1.0)