How To Embedding a File in a Message Programmatically

MORE INFORMATION

Steps to Embed a File in a Message

1. Create an attachment for the message by calling the message's IMessage::CreateAttach method and pass NULL as the interface identifier.
2. Call IMAPIProps::SetProps to set PR_ATTACH_METHOD to ATTACH_OLE, indicating an OLE object.
3. Set PR_RENDERING_POSITION to indicate where the attachment should be displayed.
4. Call IMAPIProp::OpenProperty to open the PR_ATTACH_DATA_OBJ property with an IStorage object.
5. Use OleCreateFromFile to create the embedded IStorage object from the specified file.
6. Call the new storage object's IStorage::Commit method.

Example

The following code creates an attachment for a message, prompts the user for a file, and then embeds that file in the message. This code assumes the message has already been created. The pointer to the message is contained in the variable pMsg.

The following .lib files should be linked:

• Ole32.lib
• Oleaut32.lib
• Uuid.lib
• Mapi32.lib

     // BEGIN CODE
     #include <windows.h>
  
     #define USES_IID_IMAPITable
     #define USES_IID_IMessage
     #define USES_IID_IMAPIStatus
     #define INITGUID
     #include <initguid.h>
  
     #include <ole2.h>
     #include <mapiguid.h>
     #include <mapiutil.h>
     #include <mapitags.h>
  
     #define USES_OID_OLE2_STORAGE
     #define INITOID
     #include <mapioid.h>
  
     LPSTORAGE     pstg = NULL;
     LPUNKNOWN     lpUnknown = NULL;
     LPATTACH      pAtt      = NULL;
     ULONG         ulAttNum;
     HRESULT       hRes;
     OPENFILENAME  ofn;
     TCHAR         szFile[MAX_PATH];
     OLECHAR       pszFile[MAX_PATH];
  
     enum {METHOD,RENDERING,NUM_ATT_PROPS};
     SPropValue    spvAttach[NUM_ATT_PROPS];
  
     ZeroMemory((LPVOID) &ofn, sizeof ofn);
  
     // Set up structure to retrieve filename
     lstrcpy(szFile,"*.*");
     ofn.lStructSize = sizeof(ofn);
     ofn.hwndOwner   = hWnd;
     ofn.lpstrFilter = "All files\0*.*\0";
     ofn.lpstrFile   = szFile;
     ofn.nMaxFile    = MAX_PATH;
     ofn.lpstrTitle  = "Attach File";
     ofn.Flags       = OFN_NONETWORKBUTTON | OFN_FILEMUSTEXIST |
                       OFN_NOCHANGEDIR     | OFN_PATHMUSTEXIST;
  
     // Prompt user for file name
     if (GetOpenFileName(&ofn))
     {
        // Create an attachment on the message
        if (FAILED(hRes = pMsg->CreateAttach(
              NULL, (ULONG)0, &ulAttNum, &pAtt)))
           goto Quit;
  
        spvAttach[METHOD].ulPropTag = PR_ATTACH_METHOD;
        spvAttach[METHOD].Value.l = ATTACH_OLE;
  
        spvAttach[RENDERING].ulPropTag = PR_RENDERING_POSITION;
        spvAttach[RENDERING].Value.l = 0;
  
        // Save the properties we have set on the attachment
        if (FAILED(hRes = pAtt -> SetProps(
              NUM_ATT_PROPS,
              (LPSPropValue)&spvAttach,
              NULL)))
           goto Quit;
  
        // PR_ATTACH_DATA_OBJ will contain the OLE object
        if (FAILED(hRes = pAtt->OpenProperty(
              PR_ATTACH_DATA_OBJ,
              (LPIID)&IID_IStorage, 0,
              MAPI_CREATE | MAPI_MODIFY,
              (LPUNKNOWN *)&pstg)))
           goto Quit;
  
        // We must convert the file name to a Wide Character string
        // for use in the OleCreateFromFile function
        MultiByteToWideChar(CP_ACP, 0, ofn.lpstrFile, -1, pszFile, 512);
  
        // Create an embedded object in the IStorage object from the
        // contents of the specified file
        if (FAILED(hRes = OleCreateFromFile(
              CLSID_NULL, pszFile, IID_IOleObject,
              OLERENDER_NONE, NULL, NULL, pstg,
              (LPVOID FAR*)&lpUnknown)))
           goto Quit;
  
        // Call the Commit Method of the IStorage Object
        if (FAILED(hRes = pstg->Commit(STGC_DEFAULT)))
           goto Quit;
  
        // Save the changes to the Attachment
        pAtt -> SaveChanges(0);
  
     Quit:
        if (pAtt)
           pAtt -> Release();
  
        if (lpUnknown)
           lpUnknown -> Release();
  
        if (pstg)
           pstg -> Release();
  
        return hRes;
  
     // END CODE