Checked Items

TTMSFNCCheckedListBox extends the standard list box workflow with check boxes on each item. Use it for preference lists, feature toggles, filter options, and other cases where users can select more than one value without opening a separate dialog.

Populate Items

AddItem returns a TTMSFNCCheckedListBoxItem, so code can set the text and check state in the same setup block.

procedure TForm1.ConfigureCheckedListBox;
var
  Item: TTMSFNCCheckedListBoxItem;
begin
  TMSFNCCheckedListBox1.AddItem('PDF export').Checked := True;
  TMSFNCCheckedListBox1.AddItem('Email notification');

  Item := TMSFNCCheckedListBox1.AddItem('Archive copy');
  TMSFNCCheckedListBox1.CheckedItem[Item] := True;
end;

Respond to Check Changes

Use OnItemCheckChanged when another part of the form must react immediately after the user checks or unchecks an item.

procedure TForm1.FormCreate(Sender: TObject);
begin
  TMSFNCCheckedListBox1.OnItemCheckChanged := TMSFNCCheckedListBox1ItemCheckChanged;
end;

procedure TForm1.TMSFNCCheckedListBox1ItemCheckChanged(Sender: TObject;
  AItem: TTMSFNCCheckedListBoxItem);
begin
  Caption := AItem.Text + ': ' + BoolToStr(AItem.Checked, True);
end;

Read or Change Selection

Use Checked[index] when you already know the item position. Use CheckedItems when you want the full checked set. CheckAll and UncheckAll are useful for command buttons or reset actions.

procedure TForm1.SelectAllOptions;
begin
  TMSFNCCheckedListBox1.CheckAll;
end;

procedure TForm1.ShowCheckedOptions;
var
  Checked: TTMSFNCListBoxCheckedItems;
  Item: TTMSFNCCheckedListBoxItem;
  Summary: string;
begin
  Checked := TMSFNCCheckedListBox1.CheckedItems;
  Summary := '';

  for Item in Checked do
  begin
    if Summary <> '' then
      Summary := Summary + ', ';

    Summary := Summary + Item.Text;
  end;

  ShowMessage(Summary);
end;

Combining population, change events, and bulk collection

The following example loads a feature list, responds to each toggle by updating a status label, and provides a Select All / None action:

procedure TForm1.FormCreate(Sender: TObject);
var
  item: TTMSFNCCheckedListBoxItem;
begin
  for var feat in ['Compression', 'Encryption', 'Logging', 'Audit Trail'] do
  begin
    item := TMSFNCCheckedListBox1.AddItem(feat);
    item.Checked := feat = 'Logging'; // default on
  end;
end;

procedure TForm1.TMSFNCCheckedListBox1ItemCheckChanged(
  Sender: TObject; AItem: TTMSFNCCheckedListBoxItem);
begin
  lblStatus.Caption := AItem.Text +
    IfThen(AItem.Checked, ' enabled', ' disabled');
end;

procedure TForm1.btnSelectAllClick(Sender: TObject);
begin
  TMSFNCCheckedListBox1.CheckAll;
end;

procedure TForm1.btnApplyClick(Sender: TObject);
var
  checked: TArray<TTMSFNCCheckedListBoxItem>;
  s: string;
begin
  checked := TMSFNCCheckedListBox1.CheckedItems;
  for var item in checked do
    s := s + item.Text + ', ';
  ShowMessage('Active features: ' + s.TrimRight([',', ' ']));
end;