Objective-c 版本

UIColor * __nullable UIColorFromHexValue(NSUInteger hexValue) {
    
    CGFloat red = (hexValue & 0xFF0000) >> 16;
    CGFloat green = (hexValue & 0x00FF00) >> 8;
    CGFloat blue = hexValue & 0x0000FF;
 
    return [UIColor colorWithRed:red/255.0 green:green/255.0 blue:blue/255.0 alpha:1.0];
}

使用

// 复制上面代码放在任意头文件中，并引用该头文件，在需要的地方调用如下
UIColor *color = UIColorFromHexValue(0xFFFFFF);

Swift 版本

extension UIColor {

    static func hex(_ hexValue: UInt) -> UIColor {
        
        let red = (hexValue & 0xFF0000) >> 16
        let green = (hexValue & 0x00FF00) >> 8
        let blue = hexValue & 0x0000FF
        
         return UIColor(red: CGFloat(red)/255.0, green: CGFloat(green)/255.0, blue: CGFloat(blue)/255.0, alpha: 1.0)
    }
}

使用

let color = UIColor.hex(0xFFFFFF);