CustomTaskPane wont close completely

Question

When I close a CustomTaskPane and change the worksheet, it seems that a pane wasn't removed completely. And the Worksheet area of size of CustomTaskPane becomes inactive.

Here is how I am doing in code:

ctp.Visible = false;

And in PaneVisibleChanged event:

 private void PaneVisibleChanged(object sender, EventArgs e)
    {
        CustomTaskPane pane = (CustomTaskPane)sender;
        if (!pane.Visible)
        {
            pane.Control.Dispose();
            CustomTaskPanes.Remove(pane);
        }
    }

Observation: It happens when I have two CustomTaskPanes side by side and I am closing one.

When you say "isn't gone completely", I assume you mean the task pane is gone, but something is off with the way Excel renders ("phantom" stuff), is that right? And why are you trying to dispose that TaskPane - why not let it be? — Mathias, Jul 04 '12 at 17:35
Yes. Thats correct. When user closes the pane, I need to catch that event of visibility changed and perform task. One my my functionality requires CustomTaskPane to auto close/be invisible, so I need to handle that. While doing that I have observed the UI rendering issue. — Cannon, Jul 05 '12 at 19:47
What I don't understand is why you are going through the effort of disposing everything. What's the problem with simply having the TaskPane be invisible? — Mathias, Jul 05 '12 at 20:30
Just want to note, that you do not have to call "pane.Control.Dispose();" by your own in the above code, because "CustomTaskPanes.Remove(pane);" does itself call "Dispose()" on your UserControl. You can see this by checking the property "pane.Control.IsDisposed". — jreichert, Jun 06 '14 at 12:13

score 0 · Answer 1 · answered Jan 25 '13 at 04:26

I'm facing a similar issue with a custom task pane not disposing correctly in VSTO Excel 2010. The code I'm using that tries to fix the issue is simple:

var taskbar = Globals.ThisWorkbook.Application.CommandBars["Task Pane"];
taskbar.Reset();

The Visible event of the side panel does not seem to work ok for me. I usually show or hide the task pane like this:

Globals.ThisWorkbook.Application.CommandBars["Task Pane"].Visible = false;

CustomTaskPane wont close completely

1 Answers1