Question

I am adding a few different file types to slides in powerpoint. These types include mp4, zip, swf, and other formats. I am not looking for a way to play these file types back; however, I’d like to store and retrieve files from within a powerpoint preso.

I’ve successfully stored these various file types by doing the following:

currentSlide.Shapes.AddOLEObject(0, 0, -1, -1, "", this.filePath);

I can also retrieve them manually by Right Clicking the Object -> Selecting Edit Package -> File -> Save Content.

I am looking to replicate or use this functionality to save the contents of the OLEObject back to its original state and to a path I specify. I have a way to find that shape and I think this object contains the contents: slideShape.OLEFormat.ObjectI just don’t know what to do now. Ideas? Thanks.

Oh I am using office 2010, if that makes any sort of difference.

Answer 1

So, I know this is late; however, I know others must have similar questions.

I contacted Microsoft about this issue and it took them around a month or so, but they finally got me an answer. I have a zip of the solution. It is fairly extensive, look below for just plain source code.

First some instructions:

1) Create a PowerPoint presentation and embed some files in it (Video, mp3, zip etc)
2) Save the file to the following location C:\Temp\Temp.pptx
3) Close the file
4) Create a folder “GeneratedFiles” under “C:\Temp”
5) Open the application and run it.

So the only downside is that the PPTX file must be closed. That being said, one might be able to copy the open PPTX file elsewhere and then extracted the files from that location rather than the PPTX that is actually being worked on. Then just delete the temporary one. We will see. This is as close as this solution gets though.

Without further adieu:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.IO.Packaging;
using System.Runtime.InteropServices;
using System.IO;

namespace ExtractOLEPowerPoint
{
class Program
{

    #region IEnumSTATSTG
    [ComImport]
    [Guid("0000000d-0000-0000-C000-000000000046")]
    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    public interface IEnumSTATSTG
    {
        // The user needs to allocate an STATSTG array whose size is celt.
        [PreserveSig]
        uint Next(uint celt, [MarshalAs(UnmanagedType.LPArray), Out] System.Runtime.InteropServices.ComTypes.STATSTG[] rgelt, out uint pceltFetched);

        void Skip(uint celt);

        void Reset();

        [return: MarshalAs(UnmanagedType.Interface)]
        IEnumSTATSTG Clone();
    }
    #endregion

    //#region IStream

    //[ComImport, Guid("0000000c-0000-0000-C000-000000000046"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    //public interface IStream
    //{
    //    void Read([Out, MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 1)] byte[] pv, uint cb, out uint pcbRead);
    //    void Write([MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 1)] byte[] pv, uint cb, out uint pcbWritten);
    //    void Seek(long dlibMove, uint dwOrigin, out long plibNewPosition);
    //    void SetSize(long libNewSize);
    //    void CopyTo(IStream pstm, long cb, out long pcbRead, out long pcbWritten);
    //    void Commit(uint grfCommitFlags);
    //    void Revert();
    //    void LockRegion(long libOffset, long cb, uint dwLockType);
    //    void UnlockRegion(long libOffset, long cb, uint dwLockType);
    //    void Stat(out STATSTG pstatstg, uint grfStatFlag);
    //    void Clone(out IStream ppstm);
    //}

    //#endregion

    #region STATFLAG

    [Flags]
    public enum STATFLAG : uint
    {
        STATFLAG_DEFAULT = 0,
        STATFLAG_NONAME = 1,
        STATFLAG_NOOPEN = 2
    }

    #endregion

    #region IStorage
    [ComImport]
    [Guid("0000000b-0000-0000-C000-000000000046")]
    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    interface IStorage
    {
        void CreateStream(
            /* [string][in] */ string pwcsName,
            /* [in] */ uint grfMode,
            /* [in] */ uint reserved1,
            /* [in] */ uint reserved2,
            /* [out] */ out System.Runtime.InteropServices.ComTypes.IStream ppstm);
        void OpenStream(
            /* [string][in] */ string pwcsName,
            /* [unique][in] */ IntPtr reserved1,
            /* [in] */ uint grfMode,
            /* [in] */ uint reserved2,
            /* [out] */ out System.Runtime.InteropServices.ComTypes.IStream ppstm);

        void CreateStorage(
            /* [string][in] */ string pwcsName,
            /* [in] */ uint grfMode,
            /* [in] */ uint reserved1,
            /* [in] */ uint reserved2,
            /* [out] */ out IStorage ppstg);

        void OpenStorage(
            /* [string][unique][in] */ string pwcsName,
            /* [unique][in] */ IStorage pstgPriority,
            /* [in] */ uint grfMode,
            /* [unique][in] */ IntPtr snbExclude,
            /* [in] */ uint reserved,
            /* [out] */ out IStorage ppstg);

        void CopyTo(
            /* [in] */ uint ciidExclude,
            /* [size_is][unique][in] */ Guid rgiidExclude, // should this be an array?
            /* [unique][in] */ IntPtr snbExclude,
            /* [unique][in] */ IStorage pstgDest);

        void MoveElementTo(
            /* [string][in] */ string pwcsName,
            /* [unique][in] */ IStorage pstgDest,
            /* [string][in] */ string pwcsNewName,
            /* [in] */ uint grfFlags);

        void Commit(
            /* [in] */ uint grfCommitFlags);

        void Revert();

        void EnumElements(
            /* [in] */ uint reserved1,
            /* [size_is][unique][in] */ IntPtr reserved2,
            /* [in] */ uint reserved3,
            /* [out] */ out IEnumSTATSTG ppenum);

        void DestroyElement(
            /* [string][in] */ string pwcsName);

        void RenameElement(
            /* [string][in] */ string pwcsOldName,
            /* [string][in] */ string pwcsNewName);

        void SetElementTimes(
            /* [string][unique][in] */ string pwcsName,
            /* [unique][in] */ System.Runtime.InteropServices.ComTypes.FILETIME pctime,
            /* [unique][in] */ System.Runtime.InteropServices.ComTypes.FILETIME patime,
            /* [unique][in] */ System.Runtime.InteropServices.ComTypes.FILETIME pmtime);

        void SetClass(
            /* [in] */ Guid clsid);

        void SetStateBits(
            /* [in] */ uint grfStateBits,
            /* [in] */ uint grfMask);

        void Stat(
            /* [out] */ out System.Runtime.InteropServices.ComTypes.STATSTG pstatstg,
            /* [in] */ uint grfStatFlag);
    }

    #endregion

    #region STGM
    [Flags]
    public enum STGM : int
    {
        DIRECT           = 0x00000000,
        TRANSACTED       = 0x00010000,
        SIMPLE           = 0x08000000,
        READ             = 0x00000000,
        WRITE            = 0x00000001,
        READWRITE        = 0x00000002,
        SHARE_DENY_NONE  = 0x00000040,
        SHARE_DENY_READ  = 0x00000030,
        SHARE_DENY_WRITE = 0x00000020,
        SHARE_EXCLUSIVE  = 0x00000010,
        PRIORITY         = 0x00040000,
        DELETEONRELEASE  = 0x04000000,
        NOSCRATCH        = 0x00100000,
        CREATE           = 0x00001000,
        CONVERT          = 0x00020000,
        FAILIFTHERE      = 0x00000000,
        NOSNAPSHOT       = 0x00200000,
        DIRECT_SWMR      = 0x00400000,
    }

    #endregion

    #region StgIsStorageFile

    [DllImport("Ole32.dll")]
    static extern int StgIsStorageFile([MarshalAs(UnmanagedType.LPWStr)]string filename);

    #endregion

    #region StgOpenStorage

    [DllImport("Ole32.dll")]
    static extern int StgOpenStorage([MarshalAs(UnmanagedType.LPWStr)]string pwcsName, IStorage pstgPriority, STGM grfmode, IntPtr snbExclude, uint researved, out IStorage ppstgOpen);

    #endregion

    static void Main(string[] args)
    {
        Package pkg = Package.Open("C:\\Temp\\Temp.pptx");
        foreach (PackagePart pkgprt in pkg.GetParts())
        {
            if(pkgprt.Uri.ToString().StartsWith("/ppt/embeddings/"))
            {
                System.IO.Stream strm = pkgprt.GetStream();
                byte[] buffer = new byte[strm.Length];
                strm.Read(buffer, 0, (int)strm.Length);
                strm.Close();

                // Create a temporary file
                string targetFile = "C:\\Temp\\GeneratedFiles\\" + pkgprt.Uri.ToString().Remove(0, "/ppt/embeddings/".Length);
                System.IO.File.WriteAllBytes(targetFile, buffer);

                // Extract the contents.
                IStorage Is;
                StgOpenStorage(targetFile, null, STGM.READWRITE | STGM.SHARE_EXCLUSIVE, IntPtr.Zero, 0, out Is);
                ProcessPackage(Is);

                // Need to release the IStorage object and call GC.Collect() to free the object
                Marshal.ReleaseComObject(Is);
                Is = null;
                GC.Collect();
                GC.WaitForPendingFinalizers();

                // Delete the temporary binary file extracted
                File.Delete(targetFile);
            }
        }
    }
    static void ProcessPackage(IStorage pStg)
    {
        System.Runtime.InteropServices.ComTypes.IStream pStream;
        IEnumSTATSTG pEnumStatStg;
        uint numReturned;
        pStg.EnumElements(0, IntPtr.Zero, 0, out pEnumStatStg);
        System.Runtime.InteropServices.ComTypes.STATSTG[] ss = new System.Runtime.InteropServices.ComTypes.STATSTG[1];
        // Loop through the STATSTG structures in the storage.
        do
        {
            // Retrieve the STATSTG structure
            pEnumStatStg.Next(1, ss, out numReturned);
            if (numReturned != 0)
            {
                //System.Runtime.InteropServices.ComTypes.STATSTG statstm;
                byte[] bytT = new byte[4];
                // Check if the pwcsName contains "Ole10Native" stream which contain the actual embedded object
                if (ss[0].pwcsName.Contains("Ole10Native") == true)
                {
                    // Get the stream objectOpen the stream
                    pStg.OpenStream(ss[0].pwcsName, IntPtr.Zero, (uint)STGM.READ | (uint)STGM.SHARE_EXCLUSIVE, 0, out pStream);
                    //pStream.Stat(out statstm, (int) STATFLAG.STATFLAG_DEFAULT);

                    IntPtr position = IntPtr.Zero;
                    // File name starts from 7th Byte.
                    // Position the cursor to the 7th Byte.
                    pStream.Seek(6, 0, position);

                    IntPtr ulRead = new IntPtr();
                    char[] filename = new char[260];
                    int i;

                    // Read the File name of the embedded object
                    for (i = 0; i < 260; i++)
                    {
                        pStream.Read(bytT, 1, ulRead);
                        pStream.Seek(0, 1, position);
                        filename[i] = (char)bytT[0];
                        if (bytT[0] == 0)
                        {
                            break;
                        }
                    }
                    string path = new string(filename, 0, i);

                    // Next part is the source path of the embedded object.
                    // Length is unknown. Hence, loop through each byte to read the 0 terminated string
                    // Read the source path.
                    for (i = 0; i < 260; i++)
                    {
                        pStream.Read(bytT, 1, ulRead);
                        pStream.Seek(0, 1, position);
                        filename[i] = (char)bytT[0];
                        if (bytT[0] == 0)
                        {
                            break;
                        }
                    }
                    // Source File path
                    string fullpath = new string(filename, 0, i);

                    // Unknown 4 bytes
                    pStream.Seek(4, 1, position);

                    // Next 4 byte gives the length of the temporary file path 
                    // (Office uses a temporary location to copy the files before inserting to the document)
                    // The length is in little endian format. Hence conversion is needed
                    pStream.Read(bytT, 4, ulRead);
                    ulong dwSize, dwTemp;
                    dwSize = 0;
                    dwTemp = (ulong)bytT[3];
                    dwSize += (ulong)(bytT[3] << 24);
                    dwSize += (ulong)(bytT[2] << 16);
                    dwSize += (ulong)(bytT[1] << 8);
                    dwSize += bytT[0];

                    // Skip the temporary file path
                    pStream.Seek((long)dwSize, 1, position);

                    // Next four bytes gives the size of the actual data in little endian format.
                    // Convert the format.
                    pStream.Read(bytT, 4, ulRead);
                    dwTemp = 0;
                    dwSize = 0;
                    dwTemp = (ulong)bytT[3];
                    dwSize += (ulong)(bytT[3] << 24);
                    dwSize += (ulong)(bytT[2] << 16);
                    dwSize += (ulong)(bytT[1] << 8);
                    dwSize += (ulong)bytT[0];

                    // Read the actual file content 
                    byte[] byData = new byte[dwSize];
                    pStream.Read(byData, (int)dwSize, ulRead);

                    // Create the file
                    System.IO.BinaryWriter bWriter = new System.IO.BinaryWriter(System.IO.File.Open("C:\\temp\\GeneratedFiles\\" + path, System.IO.FileMode.Create));
                    bWriter.Write(byData);
                    bWriter.Close();
                }
            }
        }
        while (numReturned > 0);
    }
}
}