How To Write To A OneNote 2013 Page Using C# and The OneNote Interop

Question

I have seen many articles about this but all of them are either incomplete or do not answer my question. Using C# and the OneNote Interop, I would like to simply write text to an existing OneNote 2013 Page. Currently I have a OneNote Notebook, with a Section titled "Sample_Section" and a Page called "MyPage".

I need to be able to use C# code to write text to this Page, but I cannot figure out how or find any resources to do so. I have looked at all of the code examples on the web and none answer this simple question or are able to do this. Also many of the code examples are outdated and break when attempting to run them.

I used the Microsoft code sample that shows how to change the name of a Section but I cannot find any code to write text to a Page. There is no simple way to do this that I can see. I have taken a lot of time to research this and view the different examples online but none are able to help.

I have already viewed the MSDN articles on the OneNote Interop as well. I vaguely understand how the OneNote Interop works through XML but any extra help understanding that would also be appreciated. Most importantly I would really appreciate a code example that demonstrates how to write text to a OneNote 2013 Notebook Page.

I have tried using this Stack Overflow answer: Creating new One Note 2010 page from C#

However, there are 2 things about this solution that do not answer my question:

1) The marked solution shows how to create a new page, not how to write text to it or how to populate the page with any information.

2) When I try to run the code that is marked as the solution, I get an error at the following line:

var node = doc.Descendants(ns + nodeName).Where(n => n.Attribute("name").Value == objectName).FirstOrDefault();
return node.Attribute("ID").Value;

The reason being that the value of "node" is null, any help would be greatly appreciated.

Answer 1

I asked the same question on MSDN forums and was given this great answer. Below is a nice, clean example of how to write to OneNote using C# and the OneNote interop. I hope that this can help people in the future.

    static Application onenoteApp = new Application();
    static XNamespace ns = null;

    static void Main(string[] args)
    {
        GetNamespace();
        string notebookId = GetObjectId(null, OneNote.HierarchyScope.hsNotebooks, "MyNotebook");
        string sectionId = GetObjectId(notebookId, OneNote.HierarchyScope.hsSections, "Sample_Section");
        string firstPageId = GetObjectId(sectionId, OneNote.HierarchyScope.hsPages, "MyPage");
        GetPageContent(firstPageId);
        Console.Read();
    }
    static void GetNamespace()
    {
        string xml;

        onenoteApp.GetHierarchy(null, OneNote.HierarchyScope.hsNotebooks, out xml);
        var doc = XDocument.Parse(xml);
        ns = doc.Root.Name.Namespace;
    }

    static string GetObjectId(string parentId, OneNote.HierarchyScope scope, string objectName)
    {
        string xml;
        onenoteApp.GetHierarchy(parentId, scope, out xml);

        var doc = XDocument.Parse(xml);
        var nodeName = "";

        switch (scope)
        {
            case (OneNote.HierarchyScope.hsNotebooks): nodeName = "Notebook"; break;
            case (OneNote.HierarchyScope.hsPages): nodeName = "Page"; break;
            case (OneNote.HierarchyScope.hsSections): nodeName = "Section"; break;
            default:
                return null;
        }

        var node = doc.Descendants(ns + nodeName).Where(n => n.Attribute("name").Value == objectName).FirstOrDefault();

        return node.Attribute("ID").Value;
    }
    static string GetPageContent(string pageId)
    {
        string xml;
        onenoteApp.GetPageContent(pageId, out xml, OneNote.PageInfo.piAll);
        var doc = XDocument.Parse(xml);
        var outLine = doc.Descendants(ns + "Outline").First();
        var content = outLine.Descendants(ns + "T").First();
        string contentVal = content.Value;
        content.Value = "modified";
        onenoteApp.UpdatePageContent(doc.ToString());
        return null;
    }