DirectoryEntry objDE;
//列出用户
objDE=new DirectoryEntry("LDAP://yourserver/cn=users,dc=xxx,dc=com","Administrator","pwd",System.DirectoryServices.AuthenticationTypes.ServerBind);
foreach(DirectoryEntry ch in objDE.Children)
   Response.Write(ch.Path+""+ch.SchemaClassName+"");
//建用户
DirectoryEntry objDE1=objDE.Children.Add("cn=newtest","user");
objDE1.Invoke("Put",new Object[2] {"givenName","newtest"});
objDE1.Invoke("Put",new Object[2] {"samAccountName","newtest"});
objDE1.Invoke("Put",new Object[2] {"userPrincipalName","newtest"});
objDE1.Invoke("Put",new Object[2] {"UserAccountControl","512"});
objDE1.CommitChanges();
objDE1.Invoke("ChangePassword",new Object[2] {"","pwd"});
objDE1.CommitChanges();

如果要查找所有容器下的user,用DirectorySearcher
DirectoryEntry objDE=new DirectoryEntry("LDAP://yourserver","Administrator","pwd",System.DirectoryServices.AuthenticationTypes.ServerBind);
System.DirectoryServices.DirectorySearcher mySearcher = new System.DirectoryServices.DirectorySearcher(objDE);
mySearcher.Filter = ("(objectClass=user)");
foreach(System.DirectoryServices.SearchResult resEnt in mySearcher.FindAll())
    {
        Response.Write( resEnt.Path+"--------------------------------------------------------------------------------");
    }