ComboBox-Eintraege doppelt und x-fach vorhanden

[Mackhack]

Hi DPler,

mit diesen beiden Functions ermittle ich die Workgroups und die dazugehoerigen Computernamen im Netzwerk.

Delphi-Quellcode:

function TfoNetworkConnection.GetNetComputerNames: String;
var
  I: Integer;
  hEnum: THandle;
  Entries: DWORD;
  BufferSize: DWORD;
  NetResourceBuf: Array[0..511] of TNetResource;
  NetResource: TNetResource;
begin
  if ( CbxWorkgroup.ItemIndex > -1 ) then
  begin
    CbxComputerName.Clear;
    try
      NetResource.dwScope := RESOURCE_GLOBALNET;
      NetResource.dwType := RESOURCETYPE_ANY;
      NetResource.dwDisplayType := RESOURCEDISPLAYTYPE_GENERIC;
      NetResource.dwUsage := RESOURCEUSAGE_CONNECTABLE;
      NetResource.lpLocalName := nil;
      NetResource.lpRemoteName := PChar(CbxWorkgroup.Items[CbxWorkgroup.ItemIndex]);
      NetResource.lpComment := nil;
      NetResource.lpProvider := nil;

      if ( WNetOpenEnum(RESOURCE_GLOBALNET, RESOURCETYPE_ANY, 0, @NetResource, hEnum) <> NO_ERROR ) then
      begin
        ShowMessage('Could not connect to workgroup: ' + String(NetResource.lpRemoteName) + ' Error was: 0x' + IntToHex(GetLastError, 8));
        Exit;
      end;
      Entries := DWORD(-1);
      BufferSize := DWORD(16384);
      while ( WNetEnumResource(hEnum, Entries, @NetResourceBuf[0], BufferSize) = NO_ERROR ) do
      begin
        for I := 0 to Entries - 1 do
        begin
          if ( (CompareText(NetResourceBuf[I].lpRemoteName, '\\' + GetLocalComputerName) <> 0) ) then
          begin
            CbxComputerName.Items.Add(NetResourceBuf[I].lpRemoteName)
          end;
        end;
      end;
    finally
      WNetCloseEnum(hEnum);
    end;
  end;
end;

function TfoNetworkConnection.GetWorkgroups: String;
var
  NetResourceBuf, NetResourceBuf2: Array[0..511] of TNetResource;
  I: Integer;
  J: Integer;
  hEnum, hEnum2: THandle;
  Entries: DWORD;
  Entries2: DWORD;
  BufferSize: DWORD;
begin
  if ( WNetOpenEnum(RESOURCE_GLOBALNET, RESOURCETYPE_ANY, 0, nil, hEnum) <> NO_ERROR ) then
  begin
    Exit;
  end;
  Entries := DWORD(-1);
  BufferSize := DWORD(16384);
  while ( WNetEnumResource(hEnum, Entries, @NetResourceBuf[0], BufferSize) = NO_ERROR ) do
  begin
    try
      for I := 0 to Entries - 1 do
      if ( (NetResourceBuf[I].dwUsage and RESOURCEUSAGE_CONTAINER) = RESOURCEUSAGE_CONTAINER) and (Pos('Microsoft Windows', NetResourceBuf[I].lpRemoteName) = 1 ) then
      begin
        try
          if ( WNetOpenEnum(RESOURCE_GLOBALNET, RESOURCETYPE_ANY, 0, @NetResourceBuf[I], hEnum2) <> NO_ERROR ) then
          begin
            ShowMessage('Error enumerating Microsoft Network Resources!');
            Exit;
          end;
          Entries2 := DWORD(-1);
          while ( WNetEnumResource(hEnum2, Entries2, @NetResourceBuf2[0], BufferSize) = NO_ERROR ) do
          begin
            for J := 0 to Entries2 - 1 do
            begin
              CbxWorkgroup.Items.Add(String(NetResourceBuf2[J].lpRemoteName));
            end;
          end;
        finally
          WNetCloseEnum(hEnum2);
        end;
      end;
    finally
      WNetCloseEnum(hEnum);
    end;
  end;
end;

Ich starte die Workgroupsuche mit einem Buttonclick vorerst noch. Was mir jetzt aber aufgefallen ist ist folgendes:
Wenn ich auf den Button das 2...xte mal klicke kommen alle Workgroups 2 mal, 3 mal usw. Eben so oft man auf den Button drueck so oft wird die ComboBox gefuellt. Wie kann ich diese Misere Sinnvoll ausbuegeln?

Danke!