这是一个接受十六进制字符串并返回UIColor的函数。 (你可以输入十六进制字符串格式:#ffffff或ffffff)

用法:

var color1 = hexStringToUIColor("#d3d3d3")

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: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)
    )
}

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)
    )
}

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)
    )
}

沙德源代码:/ gist: de147c42d7b3063ef7bc

另一个带有alpha的版本

#define UIColorFromRGBA(rgbValue) [UIColor colorWithRed:((float)((rgbValue & 0xFF000000) >> 24))/255.0 green:((float)((rgbValue & 0xFF0000) >> 16))/255.0 blue:((float)((rgbValue & 0xFF00) >> 8 ))/255.0 alpha:((float)((rgbValue & 0xFF))/255.0)]

上面的几个解决方案涉及到一些不必要的nsstring使用。这个UIColor类扩展更简单更快:

+ colorWithHex:(UInt32)hex alpha:(CGFloat)alpha
{
    return [UIColor colorWithRed:((hex & 0xFF0000) >> 16)/255.0
                           green:((hex & 0x00FF00) >> 8)/255.0
                            blue:( hex & 0x0000FF)/255.0
                           alpha:alpha];
}

简单来说:

return [UIColor colorWithHex:0x006400 alpha:1.0]; // HTML darkgreen

swift 2.0+。 这段代码对我来说很好。

extension UIColor {
    /// UIColor(hexString: "#cc0000")
    internal convenience init?(hexString:String) {
        guard hexString.characters[hexString.startIndex] == Character("#") else {
            return nil
        }
        guard hexString.characters.count == "#000000".characters.count else {
            return nil
        }
        let digits = hexString.substringFromIndex(hexString.startIndex.advancedBy(1))
        guard Int(digits,radix:16) != nil else{
            return nil
        }
        let red = digits.substringToIndex(digits.startIndex.advancedBy(2))
        let green = digits.substringWithRange(Range<String.Index>(start: digits.startIndex.advancedBy(2),
            end: digits.startIndex.advancedBy(4)))
        let blue = digits.substringWithRange(Range<String.Index>(start:digits.startIndex.advancedBy(4),
            end:digits.startIndex.advancedBy(6)))
        let redf = CGFloat(Double(Int(red, radix:16)!) / 255.0)
        let greenf = CGFloat(Double(Int(green, radix:16)!) / 255.0)
        let bluef = CGFloat(Double(Int(blue, radix:16)!) / 255.0)
        self.init(red: redf, green: greenf, blue: bluef, alpha: CGFloat(1.0))
    }
}

此代码包括字符串格式检查。 如。

let aColor = UIColor(hexString: "#dadada")!
let failed = UIColor(hexString: "123zzzz")

据我所知，我的代码在维护可失败条件的语义和返回可选值方面没有任何缺点。这应该是最好的答案。

一个伟大的Swift实现(为Xcode 7更新)使用扩展，从各种不同的答案和地方拉到一起。在结尾还需要字符串扩展名。

Use:

let hexColor = UIColor(hex: "#00FF00")

注意:我添加了一个选项，为alpha通道的标准6位十六进制值的末尾添加2个额外的数字(传入值为00-99)。如果这冒犯了你，就把它拿掉。您可以实现它来传递一个可选的alpha参数。

扩展:

extension UIColor {

    convenience init(var hex: String) {
        var alpha: Float = 100
        let hexLength = hex.characters.count
        if !(hexLength == 7 || hexLength == 9) {
            // A hex must be either 7 or 9 characters (#RRGGBBAA)
            print("improper call to 'colorFromHex', hex length must be 7 or 9 chars (#GGRRBBAA)")
            self.init(white: 0, alpha: 1)
            return
        }

        if hexLength == 9 {
            // Note: this uses String subscripts as given below
            alpha = hex[7...8].floatValue
            hex = hex[0...6]
        }

        // Establishing the rgb color
        var rgb: UInt32 = 0
        let s: NSScanner = NSScanner(string: hex)
        // Setting the scan location to ignore the leading `#`
        s.scanLocation = 1
        // Scanning the int into the rgb colors
        s.scanHexInt(&rgb)

        // Creating the UIColor from hex int
        self.init(
            red: CGFloat((rgb & 0xFF0000) >> 16) / 255.0,
            green: CGFloat((rgb & 0x00FF00) >> 8) / 255.0,
            blue: CGFloat(rgb & 0x0000FF) / 255.0,
            alpha: CGFloat(alpha / 100)
        )
    }
}

字符串扩展: 浮动的来源 下标源

extension String {

    /**
    Returns the float value of a string
    */
    var floatValue: Float {
        return (self as NSString).floatValue
    }

    /**
    Subscript to allow for quick String substrings ["Hello"][0...1] = "He"
    */
    subscript (r: Range<Int>) -> String {
        get {
            let start = self.startIndex.advancedBy(r.startIndex)
            let end = self.startIndex.advancedBy(r.endIndex - 1)
            return self.substringWithRange(start..<end)
        }
    }
}

使用Xcode的原生颜色文字功能来轻松地添加十六进制颜色。

在你的代码中输入颜色文字，然后让Xcode自动完成剩下的工作。

颜色选择界面将允许你粘贴十六进制颜色:#FF9300

宏的git差异将显示RGB值而不是十六进制值:

let orange = #colorLiteral(red: 1, green: 0.5763723254, blue: 0, alpha: 1)

但它仍然是一种简单的方法来粘贴十六进制没有任何第三方工具或扩展。