Question

How would I go about creating multiple documents when a single file is opening in a MFC application?

We have an aggregate file format which can contain information for multiple documents. When this file is opened, I would like multiple CDocuments created for each record in the file. We already have a extended CDocManager, so I’m guessing this could be implemented by some logic in OpenDocumentFile. The question is how to pass the information about ‘I am record x of y’ back up from the CDocument class to the doc manager?

Answer 1

If you have several CDocument derived types that store different information, you need a seperate CMultiDocTemplate for each type, typically stored in your CApp derived class. When you call App.Initinstance you initialise each template using something like

m_MyTempate1 = new CAtlasMDITemplate(IDR_RES_TYPE1,          RUNTIME_CLASS(CDocumentType1),     RUNTIME_CLASS(CChildFrameSplitter),      RUNTIME_CLASS(CViewType1)); 

When you open your base document, you then create and retrieve your additional documents. There are a number of places you could do this in, Serialize probably being the easiest, e.g.

void CDocumentType1::Serialize(CArchive& ar) { // //  Do all the document type 1 serialisation //  // Create second doc  CDocumentType2 *pDoc2 = theApp.m_MyTempate2->OpenDocumentFile(NULL); pDoc2->Serialize(ar);  } 

The more conventional way of doing this though would be to have a single document, with multiple views for accessing the different parts of the aggregate document.