Word Document Automation with .NET 4: Attach Styles From a Template

I’ve been working with document generation a bit lately. The latest hurdle I’ve had to jump is related to styles. I’ve found that the technique I’m using to merge styles is nice and easy but has one undesired feature: each source doc brings its own styles with it, overwriting any existing styles that have already been imported as it goes. This is nice in a lot of ways, but not what I want at the moment.

After a lot of trial and error, I’ve come up with a super simple way to apply a single set of styles to the finished document:

public static void StyleDocument(Document document, string templateFile)
{
    document.CopyStylesFromTemplate(templateFile);
}

That’s it! This will take all the styles from the given .dotx or .docx file and apply them to the given document object. If you only have a file path of the document that needs to be styled, you’ll need to open/close it, too, with this overload (in addition to the above method):

public static void StyleDocument(string file, string templateFile)
{
    Application WordApp = null;

    try
    {
        WordApp = new Application();
        var Document = WordApp.Documents.Open(file);
        StyleDocument(Document, templateFile);
    }
    finally
    {
        DisposeApp(WordApp);
    }
}

Where DisposeApp(...) is just a helper to cleanup my mess:

private static void DisposeApp(Application WordApp)
{
    if (WordApp != null)
    {
        foreach (var Doc in WordApp.Documents)
        {
            (Doc as _Document).Close();
        }
        (WordApp as _Application).Quit();

        System.Runtime.InteropServices.Marshal.FinalReleaseComObject(WordApp);
    }
}

This technique is far, far nicer than working with the styles manually.