could not capture down arrow in combobox in wpf

Question

I have a combobox on a window in wpf and i am trying to capture the down arrow key of this combobox but i am not able to do so. The following is the only code i have for the com

Answer 1

This code is helpful for me.

    
        item1
        item2
        item3
    

CodeBehind

private void StackPanel_PreviewKeyDown(object sender, KeyEventArgs e)
{
    if (e.Key == Key.Down)
    {

    }
}