Search user of specific domain name

Usually, we use a LDAP search filter to find a user. The filter like"(Samaccountname = user alias)".

But there is a special situation is: the domain what the LDAP path assign has several sub-domains, and there are several users of these sub-domains have same alias.

E. g.
The LDAP path is" GC: // dc = root, Dc = com ".
There are two sub-domains of root domain:
GC: // dc = sub1, Dc = root, Dc = com
GC: // dc = sub2, Dc = root, Dc = com
There are two users are:
Sub1 \ Username
Sub2 \ Username

We cannot write a filter like" (! (Domainname = Domain Name) (samaccountname = user alias )) ". If we use the filter" (Samaccountname = user alias) "To search from" GC: // dc = root, Dc = com ", We will get two results.

Which is our real target?

So, we must identify the distinguishedname of the user with regular expression"DC * = [^,] +"To get the use's domain name.

SearchresultcollectionResults = mysearcher. findall ();

// Check domain name

Foreach ( Searchresult Result In Results)

{

StringDN = result. properties ["Distinguishedname"] [0]. tostring ();

Match M = RegEx . Match (DN, "DC * = [^,] +" );

String Mvalue = RegEx . Replace (M. value, @ "[\ S]" , "" , Regexoptions . Ignorecase );

If ( String . Compare (mvalue, "DC =" + Userdomain, True ) = 0)

{

// The target is found

}

}