self.view.backgroundColor = colorWithHex(hex: yourColorCode)

从hexaDecimalCode创建颜色的代码

func colorWithHex (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)
    )
}

Swift 2.0 - Xcode 7.2

为UIColor添加扩展。

文件-新建- Swift文件-命名。添加以下内容。

extension UIColor {
    convenience init(hexString:String) {
        let hexString:NSString = hexString.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet())
        let scanner            = NSScanner(string: hexString as String)
        if (hexString.hasPrefix("#")) {
            scanner.scanLocation = 1
        }

        var color:UInt32 = 0
        scanner.scanHexInt(&color)

        let mask = 0x000000FF
        let r = Int(color >> 16) & mask
        let g = Int(color >> 8) & mask
        let b = Int(color) & mask

        let red   = CGFloat(r) / 255.0
        let green = CGFloat(g) / 255.0
        let blue  = CGFloat(b) / 255.0
        self.init(red:red, green:green, blue:blue, alpha:1)
    }

    func toHexString() -> String {
        var r:CGFloat = 0
        var g:CGFloat = 0
        var b:CGFloat = 0
        var a:CGFloat = 0
        getRed(&r, green: &g, blue: &b, alpha: &a)
        let rgb:Int = (Int)(r*255)<<16 | (Int)(g*255)<<8 | (Int)(b*255)<<0
        return NSString(format:"#%06x", rgb) as String
    }        
}

用法:

Ex. Setting Button's color from hexCode.
    override func viewWillAppear(animated: Bool) {
        loginButton.tintColor = UIColor(hexString: " hex code here ")
}

Ex. Converting Button's current color to hex Code.

    override func viewWillAppear(animated: Bool) {
        let hexString = loginButton.tintColor.toHexString()
        print("HEX STRING: \(hexString)")

    }

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")

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)]

我找到了一个很好的UIColor类别，UIColor+PXExtensions。

用法:UIColor *mycolor = [UIColor pxColorWithHexValue:@"#BADA55"];

而且，为了防止链接到我的要点失败，这里是实际的实现代码:

//
//  UIColor+PXExtensions.m
//

#import "UIColor+UIColor_PXExtensions.h"

@implementation UIColor (UIColor_PXExtensions)

+ (UIColor*)pxColorWithHexValue:(NSString*)hexValue
{
    //Default
    UIColor *defaultResult = [UIColor blackColor];

    //Strip prefixed # hash
    if ([hexValue hasPrefix:@"#"] && [hexValue length] > 1) {
        hexValue = [hexValue substringFromIndex:1];
    }

    //Determine if 3 or 6 digits
    NSUInteger componentLength = 0;
    if ([hexValue length] == 3)
    {
        componentLength = 1;
    }
    else if ([hexValue length] == 6)
    {
        componentLength = 2;
    }
    else
    {
        return defaultResult;
    }

    BOOL isValid = YES;
    CGFloat components[3];

    //Seperate the R,G,B values
    for (NSUInteger i = 0; i < 3; i++) {
        NSString *component = [hexValue substringWithRange:NSMakeRange(componentLength * i, componentLength)];
        if (componentLength == 1) {
            component = [component stringByAppendingString:component];
        }
        NSScanner *scanner = [NSScanner scannerWithString:component];
        unsigned int value;
        isValid &= [scanner scanHexInt:&value];
        components[i] = (CGFloat)value / 256.0f;
    }

    if (!isValid) {
        return defaultResult;
    }

    return [UIColor colorWithRed:components[0]
                           green:components[1]
                            blue:components[2]
                           alpha:1.0];
}

@end

你可以使用这个库

https://github.com/burhanuddin353/TFTColor

斯威夫特

UIColor.colorWithRGB(hexString: "FF34AE" alpha: 1.0)

objective - c

[UIColor colorWithRGBHexString:@"FF34AE" alpha:1.0f]