颜色转换

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

{

 

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

 

    // String should be 6 or 8 characters

    if ([cString length] < 6) return nil;

 

    // strip 0X if it appears

    if ([cString hasPrefix:@"0X"]) cString = [cString substringFromIndex:2];

    if ([cString hasPrefix:@"#"]) cString = [cString substringFromIndex:1];

    if ([cString length] != 6) return nil;

    // Separate into r, g, b substrings

    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];

 

    // Scan values

    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];

}