Powerpoint 2010 VSTO AddIn taskpane on multiple Windows

Question

I would like have a taskpane displayed on each document-windows, I have read all MSDN articles about it, but it doesn't work.

I click on ToggleButton1 when 3 or 4 document are open, and i get 3 or 4 TaskPanes, but on same document window.

Edit :

I think i don't have correctly explain the problem, sorry.

New try : I click on ToggleButton1 on Presentation 1 window when 3 or 4 document are open, and i get 3 or 4 TaskPanes inside Prestation 1 window, windows from other presentation are empty.

What i want is a shared taskpane and synchronized visibility accross all presentations

ThisAddin.vb

Public Class ThisAddin

    Public Sub Test()
        For Each w As PowerPoint.DocumentWindow In Application.Windows

            Me.CustomTaskPanes.Add(New UserControl1, "abc", w).Visible = True

        Next
    End Sub
End Class

Ribbon1.vb

Private Sub ToggleButton1_Click(ByVal sender As System.Object, ByVal e As Microsoft.Office.Tools.Ribbon.RibbonControlEventArgs) Handles ToggleButton1.Click

    Globals.ThisAddIn.test()

End Sub

I also have tried with :

For Each w As PowerPoint.Presentation In Application.Presentations

Answer 1

In PowerPoint, the task panes are shared across all document windows. As you switch between presentation windows, the same task pane is used (this is why you get 3 or 4 panes when you add task panes for each window - they are shared across presentations). If you want separate task panes you need to open/close the active task panes (or separately manage task pane state per presentation) as you change the active DocumentWindow