我最终为UIColor创建了一个类别，我可以在我的其他项目中重用，并添加了这个函数:

+ (UIColor *)colorFromHex:(unsigned long)hex
{
    return [UIColor colorWithRed:((float)((hex & 0xFF0000) >> 16))/255.0
                           green:((float)((hex & 0xFF00) >> 8))/255.0
                            blue:((float)(hex & 0xFF))/255.0
                           alpha:1.0];
}

用法是这样的:

UIColor *customRedColor = [UIColor colorFromHex:0x990000];

这比传递字符串并将其转换为数字然后移位位要快得多。

你也可以从你的.pch文件中导入类别，这样你就可以很容易地在你的应用程序中到处使用colorFromHex，就像它内置到UIColor中一样:

#ifdef __OBJC__
    #import <UIKit/UIKit.h>
    #import <Foundation/Foundation.h>
    // Your other stuff here...
    #import "UIColor+HexColor.h"
#endif

据我所知，没有从十六进制字符串到UIColor(或CGColor)的内置转换。但是，您可以很容易地为此目的编写几个函数—例如，参见iphone开发访问uicolor组件

十六进制初始化

extension UIColor{
public  convenience init(hex : String) {
    var cString:String = hex.trimmingCharacters(in: .whitespacesAndNewlines).uppercased()

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

    if ((cString.count) != 6) {
        self.init(red: 1, green: 1, blue: 1, alpha: 1)
        return
    }

    var rgbValue:UInt32 = 0
    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: CGFloat(1.0)
    )
}


//Iniitailization
let myColor = UIColor(hex: "#452b4e")

编码愉快!享受! !

有cocoapod支持，这很好

https://github.com/mRs-/HexColors

// with hash
NSColor *colorWithHex = [NSColor colorWithHexString:@"#ff8942" alpha:1];

// wihtout hash
NSColor *secondColorWithHex = [NSColor colorWithHexString:@"ff8942" alpha:1];

// short handling
NSColor *shortColorWithHex = [NSColor colorWithHexString:@"fff" alpha:1]

斯威夫特4

你可以像这样在扩展中创建一个非常方便的构造函数:

extension UIColor {
    convenience init(hexString: String, alpha: CGFloat = 1.0) {
        var hexInt: UInt32 = 0
        let scanner = Scanner(string: hexString)
        scanner.charactersToBeSkipped = CharacterSet(charactersIn: "#")
        scanner.scanHexInt32(&hexInt)

        let red = CGFloat((hexInt & 0xff0000) >> 16) / 255.0
        let green = CGFloat((hexInt & 0xff00) >> 8) / 255.0
        let blue = CGFloat((hexInt & 0xff) >> 0) / 255.0
        let alpha = alpha

        self.init(red: red, green: green, blue: blue, alpha: alpha)
    }
}

以后再用

let color = UIColor(hexString: "#AABBCCDD")

extension UIColor 
{
    class func fromHexaString(hex:String) -> UIColor
    {
        let scanner           = Scanner(string: hex)
        scanner.scanLocation  = 0
        var rgbValue: UInt64  = 0
        scanner.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)
        )
    }
}

//you can call like this.

UIColor.fromHexaString(hex:3276b1)