Build a Collapsible Task Pane in Outlook – Part 2

In part 1 of this series I gave a (brief) overview of the Outlook Task Pane and provided a couple of links to articles on MSDN that explain how to build one.

Recap – 2 Problems with Task Panes within Outlook

Building a task pane and displaying it within Outlook is easy but as I mentioned in Part 1, there are a couple of problems:

  1. Managing the multiple Task Pane instances, attaching to the Explorer and Inspector windows, and destroying each task pane when its Explorer or Inspector windows closes can be a pain.
  2. The task pane you build does not come with an “collapse” button. You know, the button with a couple of chevrons pointing in the direction it will collapse? You have to add this functionality yourself. It can be done but there are easier methods.

This brings me back to the point of this series, Add-In-Express 2009 (ADX). This tool takes care of Issue #1 and. Issue #2. Yes, ADX costs a few bucks but it’s a time-saver and it reduces development effort. Either one of those is typically reason enough for me to purchase a tool (especially if the client is paying for it).

Quick Overview of the Design for the Collapsible Task Pane

By collapsible, I mean it can be "minimized" so that it resembles the collapsed state of the ToDo Bar. The task pane has a “collapse” button and resides between the mail preview window and the ToDO bar within Outlook Explorer windows.

Here is the design for the sample add-in I will build in Part 3:


The task pane displays exactly where it should. You can see the collapse button on the upper right-hand corner of the task pane. When the user clicks that button, they will see something like this image:


In this collapsed-state, only a vertical bar displays with an “expand” button. Clicking the expand button will return the task pane to its open state.

Preview of Part 3

Next-up, I’ll dig into the code and actually build the add-in. Also, I’ll decide on what to display within the task pane besides a lame button. Not to worry, I’ll think of something useful to put there and it will be code you can steal…put to use today.


  1. gamo says:

    Good post. Thank you for sharing.

  2. Julio says:

    What about part 3? I am looking for a way to build a xobni like application or an easy one, like a outlook pane, but without the restriction “ADX’s Task Pane implementation for the Explorer is only for the bottom half of the To-Do Bar”, said by an ADX member team. Is that really possible with ADX? TIA.

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