How to avoid showing context menu if the user clicks on empty space on the WinForms TreeViewAdv?

private void treeViewAdv1_MouseDown(object sender, MouseEventArgs e)
{
   this.treeViewAdv1.BeginUpdate();
   if(this.treeViewAdv1.RMouseDownNode!=null)
      if(e.Button == MouseButtons.Right && this.treeViewAdv1.RMouseDownNode.TextBounds.Contains(this.treeViewAdv1.LastMousePositionToClient()))
      {
         this.treeViewAdv1.SelectedNode = this.treeViewAdv1.RMouseDownNode;
      }
}
private void treeViewAdv1_MouseUp(object sender, MouseEventArgs e)
{
   this.treeViewAdv1.EndUpdate(true);
}

Private Sub treeViewAdv1_MouseDown(ByVal sender As Object, ByVal e As MouseEventArgs)
   Me.treeViewAdv1.BeginUpdate()
   If Not Me.treeViewAdv1.RMouseDownNode Is Nothing Then
      If e.Button = MouseButtons.Right AndAlso Me.treeViewAdv1.RMouseDownNode.TextBounds.Contains(Me.treeViewAdv1.LastMousePositionToClient()) Then
         Me.treeViewAdv1.SelectedNode = Me.treeViewAdv1.RMouseDownNode
      End If
   End If
End Sub
Private Sub treeViewAdv1_MouseUp(ByVal sender As Object, ByVal e As MouseEventArgs)
   Me.treeViewAdv1.EndUpdate(True)
End Sub