iOS － 16進制色值轉化爲RGB

 

+ (UIColor *) colorWithHexString: (NSString *)color;

#pragma mark - 顏色轉換 IOS中十六進制的顏色轉換爲UIColor

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

{

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

    // String should be 6 or 8 characters

    if ([cString length] < 6) {

        return [UIColor clearColor];

    }

    // 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 [UIColor clearColor];

    // Separate into r, g, b substrings

    NSRange range;

    range.location = 0;

    range.length = 2;

    //r

    NSString *rString = [cString substringWithRange:range];

    //g

    range.location = 2;

    NSString *gString = [cString substringWithRange:range];

    //b

    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];

}