Article ID: 173353
Article Last Modified on 8/18/2005
APPLIES TO
- Microsoft Messaging Application Programming Interface
This article was previously published under Q173353
SUMMARY
The following code example demonstrates how to open an attachment and copy the contents to a file in the current directory.
MORE INFORMATION
Use the following steps to open an attachment and copy the contents to a file in the current directory:
- Open the Attachments table, including the following columns:
PR_ATTACH_FILENAME and PR_ATTACH_NUM.
- Open an attachment in the Attachments table.
- Create a file for the attachment.
- Copy the contents of the attachment to the newly created file.
Sample Code
/* This code assumes that you already have an IMessage object, pointed to by the variable pMsg. This IMessage object should have been opened with the MAPI_MODIFY flag. This code also assumes that PR_ATTACH_METHOD equals ATTACH_BY_VALUE. See the note that follows this sample code for more information. */ /* You should have the following define and include lines for this code to compile and link correctly: #define USES_IID_IMAPITable #define INITGUID #include <initguid.h> #include <mapiutil.h> */ HRESULT WriteAttachToFile ( LPMESSAGE pMsg ) { SizedSPropTagArray(1,g_sptMsgProps) = {1, PR_HASATTACH}; LPSPropValue pProps = NULL; HRESULT hRes = 0; ULONG cVals = 0; if (FAILED(hRes = pMsg->GetProps((LPSPropTagArray) &g_sptMsgProps, 0, &cVals, &pProps))) goto Quit; else hRes = S_OK; if (PR_HASATTACH == pProps[0].ulPropTag && pProps[0].Value.b) { LPMAPITABLE pAttTbl = NULL; LPSRowSet pRows = NULL; static SizedSPropTagArray(2,sptCols) = {2,PR_ATTACH_LONG_FILENAME, PR_ATTACH_NUM}; if (SUCCEEDED(hRes = pMsg -> OpenProperty(PR_MESSAGE_ATTACHMENTS, &IID_IMAPITable, 0, 0, (LPUNKNOWN *) &pAttTbl))) { if (SUCCEEDED(hRes = pAttTbl -> SetColumns( (LPSPropTagArray) &sptCols, TBL_BATCH))) { if (SUCCEEDED(hRes = HrQueryAllRows(pAttTbl, (LPSPropTagArray) &sptCols, NULL, NULL, 0, &pRows))) { for (ULONG i = 0; i < pRows -> cRows; i++) { LPATTACH lpAttach = NULL; // Verify we received a filename from GetProps if (! PR_ATTACH_FILENAME == pRows->aRow[i].lpProps[0].ulPropTag) break; // Verify we received an Attachment Index from GetProps if (! PR_ATTACH_NUM == pRows->aRow[i].lpProps[1].ulPropTag) break; // Open the attachment if (SUCCEEDED(hRes = pMsg->OpenAttach ( pRows->aRow[i].lpProps[1].Value.l, NULL, MAPI_BEST_ACCESS, &lpAttach))) { LPSTREAM pStrmSrc = NULL, pStrmDest = NULL; STATSTG StatInfo; // Open the property of the attachment // containing the file data if (FAILED(hRes = lpAttach->OpenProperty( PR_ATTACH_DATA_BIN, (LPIID)&IID_IStream, 0, MAPI_MODIFY, (LPUNKNOWN *)&pStrmSrc))) break; // Open an IStream interface and create the file at the // same time. This code will create the file in the // current directory. if (FAILED(hRes = OpenStreamOnFile( MAPIAllocateBuffer, MAPIFreeBuffer, STGM_CREATE | STGM_READWRITE, pRows->aRow[i].lpProps[0].Value.lpszA, NULL, &pStrmDest))) break; pStrmSrc -> Stat(&StatInfo, STATFLAG_NONAME); hRes = pStrmSrc -> CopyTo(pStrmDest, StatInfo.cbSize, NULL, NULL); // Commit changes to new stream pStrmDest -> Commit(0); // Release each of our streams pStrmDest -> Release(); pStrmSrc -> Release(); } // Release the attachment lpAttach -> Release(); } } } } FreeProws(pRows); if (pAttTbl) pAttTbl -> Release(); } Quit: MAPIFreeBuffer((LPVOID) pProps); return hRes; }
NOTE: If the attachment is a message or structured storage (OLE object), there is no PR_ATTACH_DATA_BIN property. Another attachment property, PR_ATTACH_METHOD, essentially can contain four different values that tell you what to do:
- ATTACH_BY_VALUE means that you work with the PR_ATTACH_DATA_BIN property.
- ATTACH_BY_REFERENCE means that you work with PR_ATTACH_PATHNAME; the file is not physically included.
- ATTACH_EMBEDDED_MESSAGE or ATTACH_OLE mean you call OpenProperty on PR_ATTACH_DATA_OBJ, which gives you back an IMessage or IStorage interface respectively.
For more information on the PR_ATTACH_METHOD property, see the following Microsoft Developer Network (MSDN) Web site:
Keywords: kbhowto kbmsg KB173353