how to select index in a combobox using DOWN ARROW key?

Question

I want this functionalitymy combobox has multiple values. for example: RJ11, RJ12, RJ13 and so on. AutoCompleteMode set to append and AutoCompleteSource set to listItems. all i want is when i type rj in combobox it will suggest me rj11 in combobox's text field and when i press DOWN ARROW key it should select rj11 but what it is doing is it keep searching for next possible match.

i tried :

private void comboBox1_KeyDown(object sender, KeyEventArgs e)
    {
        if(e.KeyCode == Keys.Down)
        {
            comboBox1.SelectedIndex = comboBox1.FindStringExact(comboBox1.Text);
        }
    }

but it is not working. i am very new to winform and programing. please help. and yeah sorry for my bad english.

Answer 1

You can try to refer to the following code to select the index in a combobox by using down key.

We can override the ProcessCmdkey method in your form.

Code:

protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
        {
            if ((this.ActiveControl == comboBox1) && (keyData == Keys.Down))
            {
                comboBox1.SelectedIndex = comboBox1.FindStringExact(comboBox1.Text);
                return true;
            }
            else
            {
                return base.ProcessCmdKey(ref msg, keyData);
            }
        }