Question

Is the Windows Select Users, Service Accounts, or Groups dialog:

available through an API to 3rd party developers?

Is there a “AD Browser” common dialog?

Answer 1

Directory Object Picker

Sample pseudo-code:

String SelectUsers(HWND hwndParent, IList<String> usersLdapPaths)
{
   IDsObjectPicker objPicker;
   IDataObject objData;
   PDSOP_INIT_INFO pInfo;
   LPWSTR[0..2] attr;
   HRESULT hr;

   /*
      Returns the LDAP path to the selected user, e.g.:
         LDAP://stackoverflow.com/CN=Ian Boyd,OU=Stack Users,DC=stackoverflow,DC=com

      usersLdapPaths can be null. 
      If not null then the user can mutli-select users, 
      and the selected user's LDAP paths will be returned in usersLdapPaths 
      (with the function result containing just the first user)

      If the user cancels the dialog, then the result (and usersLdapPaths ) will be empty
   */
   Result := '';

   objPicker = CreateComObject(CLSID_DsObjectPicker) as IDsObjectPicker;

   System.New(pInfo);
   try
   {
      ZeroMemory(pInfo, SizeOf(DSOP_INIT_INFO));
      pInfo.cbSize = SizeOf(DSOP_INIT_INFO);
      pInfo.pwzTargetComputer = nil; //local computer

      pInfo.cDsScopeInfos := 1;
      System.New(pInfo.aDsScopeInfos);
      try
      {
         ZeroMemory(pInfo.aDsScopeInfos, SizeOf(DSOP_SCOPE_INIT_INFO));
         pInfo.aDsScopeInfos.cbSize = SizeOf(pInfo.aDsScopeInfos);
         pInfo.aDsScopeInfos.flType = DSOP_SCOPE_TYPE_UPLEVEL_JOINED_DOMAIN;  //or DSOP_SCOPE_TYPE_TARGET_COMPUTER;
         pInfo.aDsScopeInfos.flScope = DSOP_SCOPE_FLAG_WANT_PROVIDER_LDAP;
         pInfo.aDsScopeInfos.FilterFlags.Uplevel.flBothModes = DSOP_FILTER_USERS;
         pInfo.aDsScopeInfos.FilterFlags.flDownlevel = DSOP_DOWNLEVEL_FILTER_USERS;

         if (UsersLdapPaths != null)
            pInfo.flOptions = DSOP_FLAG_MULTISELECT;

         pInfo.cAttributesToFetch := 3;
         attr[0] = "description";
         attr[1] = "name";
         attr[2] = "fullName";
         pInfo.apwzAttributeNames = @attr;

         hr = objPicker.Initialize(pInfo);
         OleCheck(hr);
         hr = objPicker.InvokeDialog(hwndParent, objData);
         OleCheck(hr);

         //the result is false if the user cancelled the dialog
         if hr = S_FALSE then
            return '';

         return ReadAttributes(objData, UsersLdapPaths);
      }
      finally
      {
         System.Dispose(pInfo.aDsScopeInfos);
      }      
   }
   finally
   {
      Dispose(pInfo);
   }
}

And the helper function (that i won’t bother to transcode from one pseudocode language to another pseudocode language):

function TActiveDirectory.ReadAttributes(ADataObject: IDataObject; AValues: TStrings): string;
var
    fmtIn: TFormatEtc;
    stgOut: TStgMedium;
    pSelList: PDS_SELECTION_LIST;
    i: Integer;
    path: string;
//  x: LongWord;
//  pVar: POleVariant;
    items: PDsSelectionArray;
begin
    Result := '';

    if Assigned(AValues) then
        AValues.Clear;

    if not Assigned(ADataObject) then
        Exit;

    stgOut.tymed := TYMED_HGLOBAL;
    fmtIn.tymed := TYMED_HGLOBAL;
    fmtIn.cfFormat := RegisterClipboardFormat(CFSTR_DSOP_DS_SELECTION_LIST);
    fmtIn.dwAspect := DVASPECT_CONTENT;
    fmtIn.lindex := -1;

    if (ADataObject.GetData(fmtIn, stgOut) <> S_OK) then
        Exit;

    pSelList := GlobalLock(stgOut.hGlobal);
    try
        if pSelList.cItems > 0 then
            items := PDsSelectionArray(@pSellist.aDsSelection)
        else
            items := nil;

        for i := 0 to pSelList^.cItems-1 do
        begin
//          path := TDsSelectionArray(pSellist.aDsSelection)[i].pwzADsPath;
            path := items[i].pwzADsPath;

            if Assigned(AValues) then
                AValues.Add(path);

            if Result = '' then
                Result := path;

{           Result := pSelList^.aDsSelection[i].pwzName+' ('+pSelList.aDsSelection[i].pwzADsPath+')';
            AValues.Add(Result);
            AValues.Add('   Class: '+pSelList^.aDsSelection[i].pwzClass); //"user"
            AValues.Add('   UPN: '+pSelList^.aDsSelection[i].pwzUPN );    //e.g. "[e-mail]"
            pVar := pSelList^.aDsSelection[i].pvarFetchedAttributes;
            for x := 0 to pSelList^.cFetchedAttributes-1 do
            begin
                AValues.Add('   '+VarToStr(pVar^));
                if x < pSelList^.cFetchedAttributes then
                    Inc(pVar);
            end;}
        end;
    finally
        GlobalUnlock(stgOut.hGlobal);
    end;
end;