Overriding ComboBox to select item by pressing index through keyboard in C#

Question

I want to override a combobox such that it can be selected by its position in the list by pressing key through keyboard.

Example:

ComboBoxMonths
  - Jan
  - Feb
  - Mar
  - Apr
  - May
  - Jun
  . . .

When 'J' is pressed Jan is selected, and 'F' for 'Feb' ,....

I want to use it like this, when

1 is pressed then Jan ,
2 for Feb , etc.

Is it possible ? If yes, How can I achieve that ?

Answer 1

This only works properly if the combo is set to DropDownList, which makes sense in your example. It also only covers 1-9. If you want to handle more than one digit, it requires more logic with timers.

public class MyComboBox : ComboBox
{
    protected override void OnKeyPress(KeyPressEventArgs e)
    {
        var index = e.KeyChar - '1';
        if( index >= 0 && index < this.Items.Count )
            this.SelectedIndex = index;

        base.OnKeyPress(e);
    }
}