Example: Bands.Add, Bands.Count, Bands

• Jul 30, 2021
• 2 minutes to read

The following sample shows how to add a new band to the tree list control. The miAddBandClick method invokes a dialog box that allows the end-user to provide the new band’s caption. The miAddBandClick event calls the GetBandByCaption method, which checks if a band with the caption specified already exists.

Delphi

procedure <Form>.miAddBandClick(Sender: TObject);
var
  ABandCaption: String;
begin
  if InputQuery('Create band', 'Specify a caption of the band', ABandCaption) then
    if GetBandByCaption(ABandCaption) <> nil then
      MessageDlg('Band with this caption already exists', mtWarning, [mbOK], 0)
    else
      with cxDBTreeList.Bands.Add do
        begin
          Caption.Text := ABandCaption;
          Caption.AlignHorz := taCenter;
        end;
end;
function <Form>.GetBandByCaption(ABandCaption: String): TcxTreeListBand;
var
  I: Integer;
begin
  Result := nil;
  for I := 0 to cxDBTreeList.Bands.Count - 1 do
    if cxDBTreeList.Bands[I].Caption.Text = ABandCaption then
    begin
      Result := cxDBTreeList.Bands[I];
      Break;
    end;
end;

C++

void __fastcall <Form>::miAddBandClick(TObject *Sender){
  String ABandCaption;
  if (InputQuery("Create band", "Specify a caption of the band", ABandCaption))
    if (GetBandByCaption(ABandCaption) != NULL)
      MessageDlg("Band with this caption already exists", mtWarning, TMsgDlgButtons()<<mbOK, 0);
    else {
      TcxTreeListBand *ABand = cxDBTreeList->Bands->Add();
      ABand->Caption->Text = ABandCaption;
      ABand->Caption->AlignHorz = taCenter;
    }
}
TcxTreeListBand* <Form>::GetBandByCaption(String ABandCaption) {
  TcxTreeListBand *Result = NULL;
  for (int I = 0; I < cxDBTreeList->Bands->Count; I++)
    if (cxDBTreeList->Bands->Items[I]->Caption->Text == ABandCaption){
      Result = cxDBTreeList->Bands->Items[I];
      break;
    }
  return Result;
}