Merge multiple word documents into one Open Xml

c#, docx, merge, openxml, openxml-sdk

Solution

Using openXML SDK only, you can use `AltChunk` element to merge the multiple document into one.

This link the-easy-way-to-assemble-multiple-word-documents and this one How to Use altChunk for Document Assembly provide some samples.

EDIT 1

Based on your code that uses `altchunk` in the updated question (update#1), here is the VB.Net code I have tested and that works like a charm for me:

Using myDoc = DocumentFormat.OpenXml.Packaging.WordprocessingDocument.Open("D:\\Test.docx", True)
        Dim altChunkId = "AltChunkId" + DateTime.Now.Ticks.ToString().Substring(0, 2)
        Dim mainPart = myDoc.MainDocumentPart
        Dim chunk = mainPart.AddAlternativeFormatImportPart(
            DocumentFormat.OpenXml.Packaging.AlternativeFormatImportPartType.WordprocessingML, altChunkId)
        Using fileStream As IO.FileStream = IO.File.Open("D:\\Test1.docx", IO.FileMode.Open)
            chunk.FeedData(fileStream)
        End Using
        Dim altChunk = New DocumentFormat.OpenXml.Wordprocessing.AltChunk()
        altChunk.Id = altChunkId
        mainPart.Document.Body.InsertAfter(altChunk, mainPart.Document.Body.Elements(Of DocumentFormat.OpenXml.Wordprocessing.Paragraph).Last())
        mainPart.Document.Save()
End Using

EDIT 2

The second issue (update#2)

This code is appending the Test2 data twice, in place of Test1 data as well.

is related to `altchunkid`.

For each document you want to merge in the main document, you need to:

- add an `AlternativeFormatImportPart` in the `mainDocumentPart` with an `Id` which must be unique. This element contains the inserted data

- add in the body an `Altchunk` element in which you set the `id` to reference the previous `AlternativeFormatImportPart`.

In your code, you are using the same Id for all the `AltChunks`. It's why you see many time the same text.

I am not sure the altchunkid will be unique with your code: `string altChunkId = "AltChunkId" + DateTime.Now.Ticks.ToString().Substring(0, 2);`

If you don't need to set a specific value, I recommend you to not set explicitly the `AltChunkId` when you add the `AlternativeFormatImportPart`. Instead, you get the one generated by the SDK like this:

VB.Net

Dim chunk As AlternativeFormatImportPart = mainPart.AddAlternativeFormatImportPart(DocumentFormat.OpenXml.Packaging.AlternativeFormatImportPartType.WordprocessingML)
Dim altchunkid As String = mainPart.GetIdOfPart(chunk)

C#

AlternativeFormatImportPart chunk = mainPart.AddAlternativeFormatImportPart(DocumentFormat.OpenXml.Packaging.AlternativeFormatImportPartType.WordprocessingML);
string altchunkid = mainPart.GetIdOfPart(chunk);

Problem

I have around 10 word documents which I generate using open xml and other stuff. Now I would like to create another word document and one by one I would like to join them into this newly created document. I wish to use open xml, any hint would be appreciable. Below is my code: ``` private void CreateSampleWordDocument() { //string sourceFile = Path.Combine("D:\\GeneralLetter.dot"); //string destinationFile = Path.Combine("D:\\New.doc"); string sourceFile = Path.Combine("D:\\GeneralWelcomeLetter.docx"); string destinationFile = Path.Combine("D:\\New.docx"); try { // Create a copy of the template file and open the copy //File.Copy(sourceFile, destinationFile, true); using (WordprocessingDocument document = WordprocessingDocument.Open(destinationFile, true)) { // Change the document type to Document document.ChangeDocumentType(DocumentFormat.OpenXml.WordprocessingDocumentType.Document); //Get the Main Part of the document MainDocumentPart mainPart = document.MainDocumentPart; mainPart.Document.Save(); } } catch { } } ``` Update( using AltChunks): ``` using (WordprocessingDocument myDoc = WordprocessingDocument.Open("D:\\Test.docx", true)) { string altChunkId = "AltChunkId" + DateTime.Now.Ticks.ToString().Substring(0, 2) ; MainDocumentPart mainPart = myDoc.MainDocumentPart; AlternativeFormatImportPart chunk = mainPart.AddAlternativeFormatImportPart( AlternativeFormatImportPartType.WordprocessingML, altChunkId); using (FileStream fileStream = File.Open("D:\\Test1.docx", FileMode.Open)) chunk.FeedData(fileStream); AltChunk altChunk = new AltChunk(); altChunk.Id = altChunkId; mainPart.Document .Body .InsertAfter(altChunk, mainPart.Document.Body.Elements<Paragraph>().Last()); mainPart.Document.Save(); } ``` Why this code overwrites the content of the last file when I use multiple files? Update 2: ``` using (WordprocessingDocument myDoc = WordprocessingDocument.Open("D:\\Test.docx", true)) { MainDocumentPart mainPart = myDoc.MainDocumentPart; string altChunkId = "AltChunkId" + DateTime.Now.Ticks.ToString().Substring(0, 3); AlternativeFormatImportPart chunk = mainPart.AddAlternativeFormatImportPart(AlternativeFormatImportPartType.WordprocessingML, altChunkId); using (FileStream fileStream = File.Open("d:\\Test1.docx", FileMode.Open)) { chunk.FeedData(fileStream); AltChunk altChunk = new AltChunk(); altChunk.Id = altChunkId; mainPart.Document .Body .InsertAfter(altChunk, mainPart.Document.Body .Elements<Paragraph>().Last()); mainPart.Document.Save(); } using (FileStream fileStream = File.Open("d:\\Test2.docx", FileMode.Open)) { chunk.FeedData(fileStream); AltChunk altChunk = new AltChunk(); altChunk.Id = altChunkId; mainPart.Document .Body .InsertAfter(altChunk, mainPart.Document.Body .Elements<Paragraph>().Last()); } using (FileStream fileStream = File.Open("d:\\Test3.docx", FileMode.Open)) { chunk.FeedData(fileStream); AltChunk altChunk = new AltChunk(); altChunk.Id = altChunkId; mainPart.Document .Body .InsertAfter(altChunk, mainPart.Document.Body .Elements<Paragraph>().Last()); } } ``` This code is appending the Test2 data twice, in place of Test1 data as well. Means I get: ``` Test Test2 Test2 ``` instead of : ``` Test Test1 Test2 ```

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