How to disable the functionalities of the caption buttons in the WinForms Docking Manager control?

this.dockingManager1.CaptionButtons[0].Click += new CancelEventHandler(button1_Click);
this.dockingManager1.CaptionButtons[1].Click += new CancelEventHandler(button1_Click);
this.dockingManager1.CaptionButtons[2].Click += new CancelEventHandler(button1_Click);
this.dockingManager1.CaptionButtons[3].Click += new CancelEventHandler(button1_Click);
void button1_Click(object sender, CancelEventArgs e)
{
   e.Cancel = true;
}

AddHandler dockingManager1.CaptionButtons(0).Click, AddressOf button1_Click
AddHandler dockingManager1.CaptionButtons(1).Click, AddressOf button1_Click
AddHandler dockingManager1.CaptionButtons(2).Click, AddressOf button1_Click
AddHandler dockingManager1.CaptionButtons(3).Click, AddressOf button1_Click
Private Sub button1_Click(ByVal sender As Object, ByVal e As CancelEventArgs)
   e.Cancel = True
End Sub