TComboBox.ItemIndex Property

Specifies the index of the selected item.

Pascal

property ItemIndex: Integer;

C++

__property int ItemIndex;

Description

Read ItemIndex to determine which item is selected. The first item in the list has index 0, the second item has index 1, and so on. If no item is selected, the value of ItemIndex is -1. If the list control supports multiple selected items, ItemIndex is the index of the selected item that has focus.

Set ItemIndex programmatically to select an item by passing in the index value.

Note: To implement the ItemIndex property in a TCustomListControl descendant, override the protected GetItemIndex and SetItemIndex methods.

C++ Examples:

Copy Code

/*
This is a very simple example showing how to create a comboBox, add to
it some choices, selecting a default value and getting the selected
value.
*/
void __fastcall TForm1::FormCreate(TObject *Sender)
{
//comboBox initialize
comb = new TComboBox(this);
comb->Parent = this;

//visual options
comb->Align = TAlign::alLeft;
comb->DoubleBuffered = true;
comb->AutoComplete = true;

//adding items to the combo box
comb->AddItem("firstChoice",NULL);
comb->AddItem("secondChoice",NULL);
comb->AddItem("thirdChoice",NULL);

//setting the default value
comb->ItemIndex = 1;
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button1Click(TObject *Sender)
{
MessageDlg("Selected text: " + comb->Text,
            mtInformation, TMsgDlgButtons() << mbOK, 0);
}

Copy Code

/*
This example uses a list box and a button on a form. The
list box contains items when the form appears. When the user
selects an item and clicks the button, the selected item in
the list box is moved to the top of the list box:
*/
void __fastcall TForm1::FormCreate(TObject *Sender)
{
  ListBox1->MultiSelect = false;
  Button1->Caption = "Move to Top";
  for (int i = 1; i <= 10; i++)
    ListBox1->Items->Add("Item " + IntToStr(i));
}

void __fastcall TForm1::Button1Click(TObject *Sender)
{
  if (ListBox1->ItemIndex >= 0 && ListBox1->ItemIndex <= 9)
    ListBox1->Items->Move(ListBox1->ItemIndex, 0);
}

Delphi Examples:

Copy Code

{
This is a very simple example showing how to create a comboBox, add to
it some choices, selecting a default value and getting the selected
value.
}
procedure TForm3.Button1Click(Sender: TObject);
begin
  MessageDlg('Selected text: ' + comb.Text, mtInformation,
            mbYesNo, 0);
end;

procedure TForm3.FormCreate(Sender: TObject);
begin
  //initialize the combo box
  comb := TComboBox.Create(Self);
  comb.Parent := Self;

  //visual options
  comb.Align := alLeft;
  comb.DoubleBuffered := true;
  comb.AutoComplete := true;

  //adding items to the combo box
  comb.AddItem('firstChoice', nil);
  comb.AddItem('secondChoice', nil);
  comb.AddItem('thirdChoice', nil);

  //setting the default value
  comb.ItemIndex := 1;
end;

Copy Code

{
This example uses a list box and a button on a form. The
list box contains items when the form appears. When the user
clicks the button, the selected item in the list box is
moved to the top of the list box:
}
procedure TForm1.Button1Click(Sender: TObject);
begin
  if (ListBox1.ItemIndex in [0..9]) then
    ListBox1.Items.Move(ListBox1.ItemIndex, 0);
end;

procedure TForm1.FormCreate(Sender: TObject);
var
  I: Integer;
begin
  ListBox1.MultiSelect := False;
  Button1.Caption := 'Move to Top';
  for I := 1 to 10 do
    ListBox1.Items.Add('Item ' + IntToStr(I));
end;