Q:

Combobox Style 'csDropDownList' in Delphi

I have created one form in delphi 7 and added one combobox on it. The combobox contains the list of items. I dont want that user can enter the value to Combobox so i have set 
combobox.style := csDropDownList;

But thorugh code i want to use combobox.text := 'New Item'; but its not working. Note that the text I want to show is not in the list of items and I don't want to add it there. Please is any solution to this?

A:

No, this is simply not the way the Windows combobox control works.
However, if you insist, and you don't care that your users will get confused, you can set Style to csDropDown and then do
procedure TForm1.ComboBox1KeyPress(Sender: TObject; var Key: Char);
begin
  Key := #0;
end;

as the combobox' OnKeyPress event. Then the user cannot enter text manually, but can only choose from the items in the list. However, you can still set the text to anything you like (even if it isn't in the list) by setting the Text property:
ComboBox1.Text := 'Sample';

A:

Set the ItemIndex property. You can get ComboBox.Items.IndexOf('New Item') to get the index of that text, if you don't already know it.
Combobox.ItemIndex := Combobox.Items.IndexOf('New item');

