Mega Code Archive
Read or write in the summary information of an Office document
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Title: Read or write in the summary information of an Office document
Question: How read or write in the summary information of an Offiche document ?
Answer:
An Office document file is a structured storage file that an application can read with the StgOpenStorage function from the Windows API. This kind of file is made of storages and streams.
COM defines a standard common property set for storing summary information about document. This information is stored in a stream under the root storage. The following function shows how you can get the author property by giving a filename :
uses ActiveX, ComObj, SysUtils;
function GetSummaryInfAuthor(FileName: TFileName): string;
var
PFileName: PWideChar;
Storage: IStorage;
PropSetStg: IPropertySetStorage;
PropStg: IPropertyStorage;
ps: PROPSPEC;
pv: PROPVARIANT;
const
FMTID_SummaryInformation: TGUID = '{F29F85E0-4FF9-1068-AB91-08002B27B3D9}';
begin
PFileName := StringToOleStr(FileName);
try
// Open compound storage
OleCheck(StgOpenStorage(PFileName, nil, STGM_DIRECT or STGM_READ or STGM_SHARE_EXCLUSIVE, nil, 0, Storage));
finally
SysFreeString(PFileName);
end;
// Summary information is in a stream under the root storage
PropSetStg := Storage as IPropertySetStorage;
// Get the IPropertyStorage
OleCheck(PropSetStg.Open(FMTID_SummaryInformation, STGM_DIRECT or STGM_READ or STGM_SHARE_EXCLUSIVE, PropStg));
// We want the author property value
ps.ulKind := PRSPEC_PROPID;
ps.propid := PIDSI_AUTHOR;
// Read this property
PropStg.ReadMultiple(1, @ps, @pv);
Result := pv.pszVal;
end;
See http://msdn.microsoft.com/library/default.asp?url=/library/en-us/com/stgasstg_7agk.asp for more information about the Summary Information Property Set.
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