How to make the DataGridViewComboBoxCell actually behave like one

Even though the DataGridViewComboBoxColumn has a property for DisplayStyle which can be set to either DropDownButton or ComboBox (or Nothing), there's virtually no difference that I can see between the two settings. What I want is to be able to type text into the control like a normal ComboBox. I was disappointed to find out that this functionality is not built in. But after some struggle tracking it down (which is why I'm posting this), I did find some information about how you can actually make it work (kind of). These are the key events:

private void dataGridView1_EditingControlShowing(object sender,
DataGridViewEditingControlShowingEventArgs e)
{
   ComboBox cbo = e.Control as ComboBox;
   if (cbo != null) {
        cbo.DropDownStyle = ComboBoxStyle.DropDown;
        cbo.AutoCompleteMode = AutoCompleteMode.SuggestAppend;
        cbo.AutoCompleteSource = AutoCompleteSource.ListItems;
        cbo.TextChanged -= new EventHandler(cbo_TextChanged);
        cbo.TextChanged += new EventHandler(cbo_TextChanged);
    }
}



private void dataGridView1_CellValidating(object sender,
DataGridViewCellValidatingEventArgs e)
{
   object eFV = e.FormattedValue;
   DataGridViewComboBoxCell cbc = dataGridView1.CurrentCell as
DataGridViewComboBoxCell;
   if (cbc != null && !cbc.Items.Contains(eFV))
   {
       cbc.Items.Insert(0, eFV);
   }
   if (dataGridView1.IsCurrentCellDirty)
   {
       dataGridView1.CommitEdit(DataGridViewDataErrorContexts.Commit);
   }

   cbc.Value = cbc.Items[0];
}



private void cbo_TextChanged(object sender, EventArgs e)
{
    dataGridView1.NotifyCurrentCellDirty( true );
}