UI之UIcolor

/**面试题 将16进制#ff3344转化为UIColor*/

- (UIColor *) stringTOColor:(NSString *)str
{
    if (!str || [str isEqualToString:@""]) {
        return nil;
    }
    unsigned red,green,blue;
    NSRange range;
    range.length = 2;
    range.location = 1;
    [[NSScanner scannerWithString:[str substringWithRange:range]] scanHexInt:&red];
    range.location = 3;
    [[NSScanner scannerWithString:[str substringWithRange:range]] scanHexInt:&green];
    range.location = 5;
    [[NSScanner scannerWithString:[str substringWithRange:range]] scanHexInt:&blue];
    UIColor *color= [UIColor colorWithRed:red/255.0f green:green/255.0f blue:blue/255.0f alpha:1];
    return color;
}