iphone开发：邮箱有效验证

判断是不是一个有效的邮箱地址。

-(BOOL)is_email_can_be_open:(NSString*)email
{
    if( (0 != [email rangeOfString:@"@"].length) && (0 != [email rangeOfString:@"."].length) )
    {
        NSMutableCharacterSet *invalidCharSet = [[[[NSCharacterSet alphanumericCharacterSet] invertedSet]mutableCopy]autorelease];
        [invalidCharSet removeCharactersInString:@"_-"];

        NSRange range1 = [email rangeOfString:@"@" options:NSCaseInsensitiveSearch];

        // If username part contains any character other than "." "_" "-"

        NSString *usernamePart = [email substringToIndex:range1.location];
        NSArray *stringsArray1 = [usernamePart componentsSeparatedByString:@"."];
        for (NSString *string in stringsArray1)
        {
            NSRange rangeOfInavlidChars=[string rangeOfCharacterFromSet: invalidCharSet];
            if(rangeOfInavlidChars.length !=0 || [string isEqualToString:@""])
            {
                return NO;
            }
        }

        NSString *domainPart = [email substringFromIndex:range1.location+1];
        NSArray *stringsArray2 = [domainPart componentsSeparatedByString:@"."];

        for (NSString *string in stringsArray2)
        {
            NSRange rangeOfInavlidChars=[string rangeOfCharacterFromSet:invalidCharSet];
            if(rangeOfInavlidChars.length !=0 || [string isEqualToString:@""])
            {
                return NO;
            }
        }

        return YES;
    }
    return NO;
}

摘自云怀空－abel

补充：移动开发 , IOS ,