Delphi 5 Select ListBox and FileListBox Programmatically

If you need to programmatically select an item in a ListBox from code in Delphi 5. There is probably another easier way to do it with newer version of Delphi, but I have to maintain a program written in Delphi 5. So, here’s how you do it.

ListBox1.ItemIndex := 2; {This selects a specified item, in this case itemindex 2}
If ListBox1.Selected[ListBox1.ItemIndex] Then Do
strItemText := ListBox1.Items.Strings[ItemIndex];

To get the count of the items in the ListBox:

procedure TForm1.Button1Click(Sender: TObject);
begin
  if ListBox1.Items.Count > 0 then
  begin
    Listbox1.Selected[0]:= True;
  end;
end

To programmatically select an item or items:

procedure TForm1.FormShow(Sender: TObject);
begin
  ListBox1.ItemIndex:=0;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
 Reselect: Integer;
begin
 if (Edit1.Text = '') or (ListBox1.ItemIndex = -1) then
   exit;
 Reselect := ListBox1.ItemIndex;
 ListBox1.Items[ListBox1.ItemIndex] := Edit1.Text;
 ListBox1.ItemIndex := Reselect;
end;

To search the string in the list of items:

procedure TformStringsValues.Button1Click(Sender: TObject);
var
  I: integer;
  TheString: string;
begin
  TheString := Edit1.Text;
  I := Listbox1.Items.IndexOf(TheString);
  if I > -1 then 
    Label1.Caption := 'Item nr ' + IntToStr(I)
  else
    ShowMessage('Not Found: ' + TheString);
end;

If you want to find an item by only giving the beginning of the string, you have to scan the items one by one in your source code (case-sensitive).

procedure TformStringsValues.Button1Click(Sender: TObject);
var
  I: integer;
  TheString: string;
  Found: Boolean;
begin
  TheString := Edit1.Text;
  I := 0;
  repeat
    Found := Pos(TheString, Listbox1.Items[I]) = 1;
    if not Found then inc(I);
  until Found or (I > Listbox1.Items.Count - 1);
  if Found then
    Label1.Caption := 'Item nr ' + IntToStr(I)
  else
    ShowMessage('Not Found: ' + TheString);
end;

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