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

Xamarin的。iOS你可以使用下面的宏来代替宏:

public UIColor UIColorFromHexValue(int value, float alpha = 1f) =>
    UIColor.FromRGBA(
        ((value & 0xFF0000) >> 16) / 255.0f,
        ((value & 0x00FF00) >> 16) / 255.0f,
        ((value & 0x0000FF) >> 16) / 255.0f,
        alpha);

用法类似:

label.TextColor = UIColorFromHexValue(0xBC1128);

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

Swift 5, iOS 14

convenience init(hex: String, alpha: CGFloat = 1.0) {
    var hexFormatted: String = hex.trimmingCharacters(in: CharacterSet.whitespacesAndNewlines).uppercased()
    
    if hexFormatted.hasPrefix("#") {
        hexFormatted = String(hexFormatted.dropFirst())
    }
    
    assert(hexFormatted.count == 6, "Invalid hex code used.")
    
    var rgbValue: UInt64 = 0
    Scanner(string: hexFormatted).scanHexInt64(&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)
}

使用任何转换器网站将十六进制颜色转换为RGB值(如果你谷歌“十六进制到RGB”，你会看到一吨)。例如，这个:http://www.rgbtohex.net/hextorgb/

然后将颜色属性更改为UIColor。例子:

self.profilePicture.layer.borderColor = [UIColor colorWithRed:0 green:167 blue:142 alpha:1.0].CGColor;

十六进制颜色值是:00a78e转换为RGB: R: 0 G: 167 B: 142

如果你给出的RGB值不在0到1.0之间，你必须将它们除以255。例子:

self.profilePicture.layer.borderColor = [UIColor colorWithRed:83.00/255.0 green:123.00/255.0 blue:53.00/255.0 alpha:1.0].CGColor; 

swift 1.2更新

class func colorWithHexString (hex:String) -> UIColor {
    var cString: NSString = hex.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet()).uppercaseString

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

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

    var rString: String = cString.substringToIndex(2)
    var gString: String = (cString.substringFromIndex(2) as NSString).substringToIndex(2)
    var bString: String = (cString.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(Float(r) / 255.0), green: CGFloat(Float(g) / 255.0), blue: CGFloat(Float(b) / 255.0), alpha: CGFloat(1))

}