How To Read Compound Document Properties Directly with VC++

This article was previously published under Q186898
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You can retrieve compound document properties from a document usingstandard interfaces without the server running or even being installed. Forinstance, you can retrieve built-in document properties such as Author,Last Modified Time, and Page Count properties of a Microsoft Office 97document as well as other custom document properties.
The following steps illustrate how you can build a compound documentproperty viewer with Microsoft Visual C++. The example is a Win32 ConsoleApplication project, and can be modified to suit your needs.

Steps to Create Sample

  1. Create a new Win32 Console Application project, and call it PropDump.
  2. Add a new file called main.cpp to your project.
  3. Copy the following code into main.cpp:
       #include <stdio.h>   #include <windows.h>   #include <ole2.h>   #include <locale.h>   // Dumps simple PROPVARIANT values.   void DumpPropVariant(PROPVARIANT *pPropVar) {      // Don't iterate arrays, just inform as an array.      if(pPropVar->vt & VT_ARRAY) {         printf("(Array)\n");         return;      }      // Don't handle byref for simplicity, just inform byref.      if(pPropVar->vt & VT_BYREF) {         printf("(ByRef)\n");         return;       }      // Switch types.      switch(pPropVar->vt) {      case VT_EMPTY:         printf("(VT_EMPTY)\n");         break;      case VT_NULL:         printf("(VT_NULL)\n");         break;      case VT_BLOB:         printf("(VT_BLOB)\n");         break;      case VT_BOOL:         printf("%s (VT_BOOL)\n",         pPropVar->boolVal ? "TRUE/YES" : "FALSE/NO");         break;      case VT_I2: // 2-byte signed int.         printf("%d (VT_I2)\n", (int)pPropVar->iVal);         break;      case VT_I4: // 4-byte signed int.         printf("%d (VT_I4)\n", (int)pPropVar->lVal);         break;      case VT_R4: // 4-byte real.         printf("%.2lf (VT_R4)\n", (double)pPropVar->fltVal);         break;      case VT_R8: // 8-byte real.         printf("%.2lf (VT_R8)\n", (double)pPropVar->dblVal);         break;         case VT_BSTR: // OLE Automation string.         {            // Translate into ASCII.            char dbcs[1024];            char *pbstr = (char *)pPropVar->bstrVal;            int i = wcstombs(            dbcs, pPropVar->bstrVal, *((DWORD *)(pbstr-4)));            dbcs[i] = 0;            printf("%s (VT_BSTR)\n", dbcs);         }         break;      case VT_LPSTR: // Null-terminated string.         {         printf("%s (VT_LPSTR)\n", pPropVar->pszVal);         }         break;      case VT_FILETIME:         {            char *dayPre[] =                         {"Sun","Mon","Tue","Wed","Thu","Fri","Sat"};            FILETIME lft;            FileTimeToLocalFileTime(&pPropVar->filetime, &lft);                SYSTEMTIME lst;            FileTimeToSystemTime(&lft, &lst);            printf("%02d:%02d.%02d %s, %s %02d/%02d/%d (VT_FILETIME)\n",               1+(lst.wHour-1)%12, lst.wMinute, lst.wSecond,               (lst.wHour>=12) ? "pm" : "am",               dayPre[lst.wDayOfWeek%7],               lst.wMonth, lst.wDay, lst.wYear);         }         break;      case VT_CF: // Clipboard format.         printf("(Clipboard format)\n");         break;      default: // Unhandled type, consult wtypes.h's VARENUM structure.         printf("(Unhandled type: 0x%08lx)\n", pPropVar->vt);         break;      }   }   // Dump's built-in properties of a property storage.   void DumpBuiltInProps(IPropertySetStorage *pPropSetStg) {      printf("\n==================================================\n");      printf("BuiltInProperties Properties...\n");      printf("==================================================\n");      IPropertyStorage *pPropStg = NULL;      HRESULT hr;      // Open summary information, getting an IpropertyStorage.      hr = pPropSetStg->Open(FMTID_SummaryInformation,      STGM_READ | STGM_SHARE_EXCLUSIVE, &pPropStg);      //hr = pPropSetStg->Open(FMTID_UserDefinedProperties,         //STGM_READ | STGM_SHARE_EXCLUSIVE, &pPropStg);      if(FAILED(hr)) {         printf("No Summary-Information.\n");         return;      }      // Array of PIDSI's you are interested in.      struct pidsiStruct {         char *name;         long pidsi;      } pidsiArr[] = {         {"Title",            PIDSI_TITLE}, // VT_LPSTR         {"Subject",          PIDSI_SUBJECT}, // ...         {"Author",           PIDSI_AUTHOR},         {"Keywords",         PIDSI_KEYWORDS},         {"Comments",         PIDSI_COMMENTS},         {"Template",         PIDSI_TEMPLATE},         {"LastAuthor",       PIDSI_LASTAUTHOR},         {"Revision Number",  PIDSI_REVNUMBER},         {"Edit Time",        PIDSI_EDITTIME}, // VT_FILENAME (UTC)         {"Last printed",     PIDSI_LASTPRINTED}, // ...         {"Created",          PIDSI_CREATE_DTM},         {"Last Saved",       PIDSI_LASTSAVE_DTM},         {"Page Count",       PIDSI_PAGECOUNT}, // VT_I4         {"Word Count",       PIDSI_WORDCOUNT}, // ...         {"Char Count",       PIDSI_CHARCOUNT},         {"Thumpnail",        PIDSI_THUMBNAIL}, // VT_CF         {"AppName",          PIDSI_APPNAME}, // VT_LPSTR         {"Doc Security",     PIDSI_DOC_SECURITY}, // VT_I4         {0, 0}      };      // Count elements in pidsiArr.      int nPidsi = 0;      for(nPidsi=0; pidsiArr[nPidsi].name; nPidsi++);      // Initialize PROPSPEC for the properties you want.      PROPSPEC *pPropSpec = new PROPSPEC [nPidsi];      PROPVARIANT *pPropVar = new PROPVARIANT [nPidsi];      for(int i=0; i<nPidsi; i++) {         ZeroMemory(&pPropSpec[i], sizeof(PROPSPEC));         pPropSpec[i].ulKind = PRSPEC_PROPID;         pPropSpec[i].propid = pidsiArr[i].pidsi;      }      // Read properties.      hr = pPropStg->ReadMultiple(nPidsi, pPropSpec, pPropVar);      if(FAILED(hr)) {         printf("IPropertyStg::ReadMultiple() failed w/error %08lx\n",                hr);      }      else {         // Dump properties.         for(i=0; i<nPidsi; i++) {            printf("%16s: ", pidsiArr[i].name);            DumpPropVariant(pPropVar + i);         }      }      // De-allocate memory.      delete [] pPropVar;      delete [] pPropSpec;      // Release obtained interface.      pPropStg->Release();   }   // Dump's custom properties of a property storage.   void DumpCustomProps(IPropertySetStorage *pPropSetStg) {      printf("\n==================================================\n");      printf("Custom Properties...\n");      printf("==================================================\n");      IPropertyStorage *pPropStg = NULL;      HRESULT hr;      IEnumSTATPROPSTG *pEnumProp;      // Open User-Defined-Properties, getting an IpropertyStorage.      hr = pPropSetStg->Open(FMTID_UserDefinedProperties,         STGM_READ | STGM_SHARE_EXCLUSIVE, &pPropStg);      if(FAILED(hr)) {         printf("No User Defined Properties.\n");         return;      }      // Get property enumerator.      hr = pPropStg->Enum(&pEnumProp);      if(FAILED(hr)) {      pPropStg->Release();         printf("Couldn't enumerate custom properties.\n");         return;      }      // Enumerate properties.      STATPROPSTG sps;      ULONG fetched;      PROPSPEC propSpec[1];      PROPVARIANT propVar[1];      while(pEnumProp->Next(1, &sps, &fetched) == S_OK) {         // Build a PROPSPEC for this property.         ZeroMemory(&propSpec[0], sizeof(PROPSPEC));         propSpec[0].ulKind = PRSPEC_PROPID;         propSpec[0].propid = sps.propid;         // Read this property.         hr = pPropStg->ReadMultiple(1, &propSpec[0], &propVar[0]);         if(!FAILED(hr)) {            // Translate Prop name into ASCII.            char dbcs[1024];            char *pbstr = (char *)sps.lpwstrName;            int i = wcstombs(dbcs, sps.lpwstrName,                             *((DWORD *)(pbstr-4)));            dbcs[i] = 0;            // Dump this property.            printf("%16s: ", dbcs);            DumpPropVariant(&propVar[0]);         }      }      // Release obtained interface.      pEnumProp->Release();      pPropStg->Release();   }   // Dump's custom and built-in properties of a compound document.   void DumpProps(char *filename) {      // Translate filename to Unicode.      WCHAR wcFilename[1024];      setlocale( LC_ALL, "" );      int i = mbstowcs(wcFilename, filename, strlen(filename));      setlocale( LC_ALL, "C" );      wcFilename[i] = 0;      IStorage *pStorage = NULL;      IPropertySetStorage *pPropSetStg = NULL;      HRESULT hr;      // Open the document as an OLE compound document.      hr = ::StgOpenStorage(wcFilename, NULL,      STGM_READ | STGM_SHARE_EXCLUSIVE, NULL, 0, &pStorage);      if(FAILED(hr)) {         if(hr == STG_E_FILENOTFOUND)            printf("File not found.");         else if(hr == STG_E_FILEALREADYEXISTS)            printf("Not a compound file.");         else            printf("StgOpenStorage() failed w/error %08lx", hr);         return;      }      // Obtain the IPropertySetStorage interface.      hr = pStorage->QueryInterface(              IID_IPropertySetStorage, (void **)&pPropSetStg);      if(FAILED(hr)) {         printf("QI for IPropertySetStorage failed w/error %08lx", hr);         pStorage->Release();         return;      }      // Dump properties.      DumpBuiltInProps(pPropSetStg);      DumpCustomProps(pPropSetStg);      // Release obtained interfaces.      pPropSetStg->Release();      pStorage->Release();   }   // Program entry-point.   void main(int argc, char **argv) {      // Validate arguments.      if(argc != 2) {         printf("- OLE Document Property Viewer\n");         printf("- Usage: %s filename", argv[0]);         return;      }      // Pass filename to the subroutine.      DumpProps(argv[1]);   }					
  4. Compile the program.
To run the example, you should copy the PropDump.exe file to a directory inyour default path; for instance c:\Windows\ or c:\Windows\Command\. Then,in a directory containing a compound document file, type PropDump followedby the name of the file. You should see output similar to the following:


BuiltInProperties Properties...

           Title: MyTitle (VT_LPSTR)         Subject: MySubject (VT_LPSTR)          Author: MyAuthor (VT_LPSTR)        Keywords: MyKeywords (VT_LPSTR)        Comments: MyComments (VT_LPSTR)        Template: Normal (VT_LPSTR)      LastAuthor: Me (VT_LPSTR) Revision Number: 8 (VT_LPSTR)       Edit Time: 01:05.47 pm, Mon 01/01/1601 (VT_FILETIME)    Last printed: (VT_EMPTY)         Created: 01:42.00 pm, Fri 05/29/1998 (VT_FILETIME)      Last Saved: 12:31.00 pm, Mon 06/01/1998 (VT_FILETIME)      Page Count: 1 (VT_I4)      Word Count: 3 (VT_I4)      Char Count: 19 (VT_I4)       Thumpnail: (VT_EMPTY)         AppName: Microsoft Word 8.0 (VT_LPSTR)    Doc Security: 0 (VT_I4)				

Custom Properties...

   _PID_LINKBASE: (VT_BLOB)       _PID_GUID: (VT_BLOB)       CustProp1: CustProp1TextValue (VT_LPSTR)       CustProp2: 77777 (VT_I4)       CustProp3: TRUE/YES (VT_BOOL)       CustProp4: 00:00.00 am, Tue 05/17/1977 (VT_FILETIME)				

Additional Notes

The IPropertyStorage and IPropertySetStorage interfaces were not defined inthe original release of COM; thus this sample code requires a system with:
  • Windows NT 4.0 or later
  • Windows 95 with Internet Explorer version 4.0 or later
  • Windows 95 with DCOM installed
Previous versions of COM specified very little with respect to propertiesand their usage, but did define a serialized format that allowed developersto store properties and property sets in an IStorage instance. The propertyidentifiers and semantics of a single property set, used for summaryinformation about a document, were also defined. At that time, it wasnecessary to create and manipulate that structure directly as a datastream. For more information on the property set serialized data formatstructure, refer to "OLE Serialized Property Set Format" in the MicrosoftDeveloper Network.

(c) Microsoft Corporation 1999, All Rights Reserved. Contributions by Joe Crump, Microsoft Corporation.

Microsoft Developer Network: Persistent Property Sets

Microsoft Developer Network: OLE Serialized Property Set Format

Excel Word Access Powerpoint Binder documentproperties builtindocumentproperties customdocumentproperties

Article ID: 186898 - Last Review: 12/05/2015 08:45:15 - Revision: 4.4

Microsoft Project 2000 Standard Edition, Microsoft Excel 2000 Standard Edition, Microsoft Visual C++ 5.0 Enterprise Edition, Microsoft Visual C++ 5.0 Professional Edition, Microsoft Excel 97 Standard Edition, Microsoft PowerPoint 97 Standard Edition, Microsoft Word 97 Standard Edition, Microsoft PowerPoint 2000 Standard Edition, Microsoft Word 2000 Standard Edition, Microsoft Excel 2002 Standard Edition, Microsoft PowerPoint 2002 Standard Edition, Microsoft Word 2002 Standard Edition

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