十六进制string转换UIColor －备用

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

{

    NSString *cString = [[stringToConvert stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];//字符串处理

    //例子，stringToConvert #ffffff

    if ([cString length] < 6)

        return DEFAULT_VOID_COLOR;//如果非十六进制，返回白色

    if ([cString hasPrefix:@"#"])

        cString = [cString substringFromIndex:1];//去掉头

    if ([cString length] != 6)//去头非十六进制，返回白色

        return DEFAULT_VOID_COLOR;

    //分别取RGB的值

    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把扫描出的制定的字符串转换成Int类型

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

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

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

    //转换为UIColor

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

                           green:((float) g / 255.0f)

                            blue:((float) b / 255.0f)

                           alpha:1.0f];

}