protected internal override bool ProcessMnemonic (char charCode)
{
if (!this.Selected)
this.Parent.ChangeSelection (this);
if (this.HasDropDownItems) {
ToolStripManager.SetActiveToolStrip (this.Parent, true);
this.ShowDropDown ();
this.DropDown.SelectNextToolStripItem (null, true);
} else
this.PerformClick ();
return true;
}