iOS 十六进制颜色UIColor+Hex

//创建UIColor的类别（分类） -->   UIColor (Hex)

//定义并实现类方法

#define DEFAULT_VOID_COLOR [UIColor whiteColor]

+ (UIColor *)colorWithHexString:(NSString *)stringToConvert

{

    NSString *cString = [[stringToConvert stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];

    

    

    if ([cString length] < 6)

        return DEFAULT_VOID_COLOR;

    if ([cString hasPrefix:@"#"])

        cString = [cString substringFromIndex:1];

    if ([cString length] != 6)

        return DEFAULT_VOID_COLOR;

    

    NSRange range;

    range.location = 0;

    range.length = 2;

    NSString *rString = [cString substringWithRange:range];

    

    range.location = 2;

    NSString *gString = [cString substringWithRange:range];

    

    range.location = 4;

    NSString *bString = [cString substringWithRange:range];

    

    

    unsigned int r, g, b;

    [[NSScanner scannerWithString:rString] scanHexInt:&r];

    [[NSScanner scannerWithString:gString] scanHexInt:&g];

    [[NSScanner scannerWithString:bString] scanHexInt:&b];

    

    return [UIColor colorWithRed:((float) r / 255.0f)

                           green:((float) g / 255.0f)

                            blue:((float) b / 255.0f)

                           alpha:1.0f];

}

使用时只要写

[UIColor colorWithHexString:@"#505050"];