如何使用OpenXML SDK 2.5从word文档复制公式？

Question

I have to use OpenXML SDK 2.5 with C# to copy formulas from one word document then append them to another word document. I tried the below code, it ran successfully but when I tried to open the file, it said there's something wrong with the content. I opened it ignoring the warning but those formulas were not displayed. They are just blank blocks.

My code:

private void CreateNewWordDocument(string document, Exercise[] exercices)
        {
            using (WordprocessingDocument wordDoc = WordprocessingDocument.Create(document, WordprocessingDocumentType.Document))
            {
                // Set the content of the document so that Word can open it.
                MainDocumentPart mainPart = wordDoc.AddMainDocumentPart();

                SetMainDocumentContent(mainPart);
                foreach (Exercise ex in exercices)
                {
                    wordDoc.MainDocumentPart.Document.Body.AppendChild(ex.toParagraph().CloneNode(true));
                }
                wordDoc.MainDocumentPart.Document.Save();
            }
        }

        // Set content of MainDocumentPart.
        private void SetMainDocumentContent(MainDocumentPart part)
        {
            string docXml =
         @"<?xml version=""1.0"" encoding=""UTF-8"" standalone=""yes""?> 
 <w:document xmlns:w=""http://schemas.openxmlformats.org/wordprocessingml/2006/main"">
     <w:body><w:p><w:r><w:t>Exercise list!</w:t></w:r></w:p></w:body>
 </w:document>";

            using (Stream stream = part.GetStream())
            {
                byte[] buf = (new UTF8Encoding()).GetBytes(docXml);
                stream.Write(buf, 0, buf.Length);
            }

        }

Answer 1

This happens because not everything that can be referenced in the paragraph is copied when you clone the paragraph. The Word XML format consists of multiple files some of which reference each other. If you copy the paragraph from one document to another you need to also copy any relationships that may exist.

The OpenXML Productivity Tool is useful for diagnosing errors like these. You can open a document with the tool and ask it to validate the document.

I created a test document that just contained a hyperlink and ran your code to copy the contents to another document. I too got an error when I attempted to load it using Word so I opened it in the Productivity Tool and saw the following output:

This shows that the hyperlink is stored as a relationship rather than inline in the paragraph and my new file references a relationship that doesn't exist. Unzipping the original file and the new file and comparing the two shows what is going on: document.xml from original:

.rels of original

document.xml of generated file

.rels of generated file

Note that in the generated file the hyperlink references relationship rId5 but that doesn't exist in the generated documents relationship file.

It's worth noting that for simple source documents the code worked without issue as there are no relationships that require copying.

There are two ways that you can solve this. The easiest way is to only copy the text of the paragraph (you'll lose all styles, images, hyperlinks etc) but it is very simple. All you need to do is change

wordDoc.MainDocumentPart.Document.Body.AppendChild(ex.toParagraph().CloneNode(true));

for

Paragraph para = wordDoc.MainDocumentPart.Document.Body.AppendChild(new Paragraph());
Run run = para.AppendChild(new Run());
run.AppendChild(new Text(ex.toParagraph().InnerText));

The more complex (and perhaps proper) way of achieving it is to find the relationships and copy them to the new document as well. The code for doing that is probably beyond the scope of what I can write here but there is an interesting article on the subject here http://blogs.msdn.com/b/ericwhite/archive/2009/02/05/move-insert-delete-paragraphs-in-word-processing-documents-using-the-open-xml-sdk.aspx .

Essentially the author of that blog post is using the Powertools for OpenXML to find relationships and copy them from one document to another.