protected virtual void HandleHeaderToolTipShowing(object sender, ToolTipShowingEventArgs e)
{
e.ColumnIndex = this.HeaderControl.ColumnIndexUnderCursor;
if (e.ColumnIndex < 0)
return;
e.RowIndex = -1;
e.Model = null;
e.Column = this.GetColumn(e.ColumnIndex);
e.Text = this.GetHeaderToolTip(e.ColumnIndex);
e.ListView = this;
this.OnHeaderToolTip(e);
}