Populate dinamically a Combobox

[marcos.digirotas]

I have a Combobox which needs to be repopulated dinamically, that is, the user type 3 characters in the ComboBox and press the return key. In this moment a query is executed and the Combobox needs to be populated with the items resulted by that query. The problem that I found is that the ComboBox.Items.Clear doesn't have the expected effect.

Here is a simple example:

• Add a TUniComboBox
• On the OnKeyDown method, add the code:

  if Key=VK_RETURN then
  begin
    UniComboBox1.Items.Clear;

    UniComboBox1.Items.Add('RIO DE JANEIRO');
    UniComboBox1.Items.Add('RIO GRANDE DO SUL');
    UniComboBox1.Items.Add('RIO GRANDE DO NORTE');
  end;

• Run the program
• Inside the ComboBox, type "RIO" and press the return key: it will appear 3 items at the  ComboBox
• Edit the typed text to "RIOS" and press the return key again

In this moment I expected that the Combobox was cleared and populated with the 3 options, but the result obtained is that the ComboBox has 6 items, as if the "UniComboBox1.Items.Clear" instruction had been ignored.

Thanks in advance!

[Sherzod]

Hi,

  if Key=VK_RETURN then
  begin
    UniComboBox1.BeginUpdate;
    UniComboBox1.Items.Clear;

    UniComboBox1.Items.Add('RIO DE JANEIRO');
    UniComboBox1.Items.Add('RIO GRANDE DO SUL');
    UniComboBox1.Items.Add('RIO GRANDE DO NORTE');
    UniComboBox1.EndUpdate;
  end;

 

[marcos.digirotas]

Thanks Sherzod,

It works perfectly!