In previous posts I talked about adding a toolbar to Word as part of your VSTO project. What I am about to describe here is particularly vital for this functionality, but it is related to most customizations that you make to Word through your VSTO project.

Although you might not realize it, and it is certainly not what I expected to happen by default, when you have a VSTO project regardless of whether you choose to create a "document" or "template" project, any changes that you make to Word through code eventually become part of the global template Normal.dot (for more information about Normal.dot have a look here and here).

You might be thinking, well is that such a bad thing? Consider the following scenario. You have a VSTO Office Word Template project and part of its functionality is to add a toolbar. As explained in my previous related post, your code has to first check if the toolbar already exists and only then, if it does not exist, should it attempt to add it. With the toolbar being saved in the global template Normal.dot by default, after the first time your project is executed on a machine the toolbar will always exist. Also get this, your toolbar will continue to exist even after you have uninstalled your project from the machine (unless of course you take steps to either delete the global template Normal.dot or you write custom code that will open the template and delete the toolbar). Now imagine you install a new version of your project to this same machine, and your new version adds a few more buttons to the toolbar. When your new code executes for the first time it will check if the toolbar already exists and the answer will be yes, because the older version of the toolbar was saved in the global template Normal.dot. Your code will then skip the part of adding the toolbar and the new buttons will never be added. Even worse, your code might try to reference those new buttons that are supposed to be there and fail.

The solution is simple, you need to save the customizations that you make to Word in your own template and not the global template Normal.dot. I would have expected this to be the default behavior when you have a VSTO Word Template project, but there you have it. So how do you instruct Word to do the "right" thing? The title of the post gives it away, the following is the code you would use to do it

    // Go through each template available in the current application

    foreach (Word.Template template in Globals.ThisDocument.Application.Templates)

    {

        // If the template is this project's template

        if (String.Compare(template.Name, Constants.TEMPLATE_NAME) == 0)

        {

            // Set this template to be the one changes are made to

            Globals.ThisDocument.Application.CustomizationContext = template;

            break;

        }

    }