Is it possible to store hidden metadata information that is tied to a specific Table or Cell within a Word document?

I am trying to store metadata (basically a unique id) along with each cell of a table in a Word document. Currently, for the add-in I'm developing, I am querying the database, and buildi开发者_C百科ng a table inside the Word document using the data that is retrieved.

I want to be able to save any of the user's edits to the document, and persist it back to the database. My initial thought was to store a unique id along with each cell in the table so that I would be able to tell which records to update. I would also like to store some sort of "isChanged" flag within each cell so that I could tell which cells were changed. I found that I could add the needed information into the "ID" property of the cell - however, that information was not retained if the user saved the document, closed it, and re-opened it. I then tried storing the data by adding a data to the "Fields" collection - but that did not work and threw a runtime error. Here is the code that I tried:

object t1 = Word.WdFieldType.wdFieldEmpty;
object val = "myValue: " + counter;
object preserveFormatting = true;
tbl.Cell(i, j).Range.Fields.Add(tbl.Cell(i, j).Range, ref t1, ref val, ref preserveFormatting);

This compiles fine, but throws this runtime error "This command is not available".

So, is this possible at all? Or am I headed in the wrong direction?

Thanks in advance.

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Wound up using "ContentControls" to store the information I needed. I used the "Title" field to store the unique id, and the "tag" field to track whether the field had been changed or not. See this link for more info: http://blogs.technet.com/gray_knowlton/archive/2010/01/15/associating-data-with-content-controls.aspx

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Since a "Word 2007 Document" is XML, you can add a namespace to the document then adore the elements with attributes from your namespace. Word should ignore your namespace when loading and saving. Moreover, you can add new elments to store any information (metadata) needed.

With that said, I have not used this technique with Word, but I have done it successfully using Excel 2003.

First thing to try, is create a bare "Word 2007 Document". In your case, add a simple two by two table. Open it with a text or XML editor and add your namespace, and adore an attribute and add an element. Open with Word make a change then save it. Open with editor and make sure your namespace attribute and element have not been changed.