# OleSaveToStream

\[System.Runtime.InteropServices.DllImport("OLE32.DLL", EntryPoint = "CreateStreamOnHGlobal")]     // Create a COM stream from a pointer in unmanaged memory     extern public static int CreateStreamOnHGlobal(IntPtr ptr, bool delete, out System.Runtime.InteropServices.ComTypes.IStream pOutStm);

    \[DllImport("OLE32.DLL", ExactSpelling = true, PreserveSig = false)]     private static extern void OleSaveToStream(IPersistStreamInit pPStm, IStream pStm);

       public int ByteSizeOfIPStreamInit(IPersistStreamInit pPersistStream)        {          int     iSzOfStreamInBytes=0;          IntPtr  ptrIStream = IntPtr.Zero;          IStream IPtrStream;

         if (CreateStreamOnHGlobal(ptrIStream, true, out IPtrStream) == 0)          {               OleSaveToStream(pPersistStream,IPtrStream);               iSzOfStreamInBytes = IStreamSizeRead(IPtrStream);          }          return (iSzOfStreamInBytes \* 2); // (Multiply By 2 because Int32 is 4 bytes; Use caution.)        }

    public int IStreamSizeRead(IStream pOutStm)     {         pOutStm.Seek(0, 0, IntPtr.Zero);// Get size of the stream and read its contents to a byte array.         System.Runtime.InteropServices.ComTypes.STATSTG fileinfo;         pOutStm.Stat(out fileinfo, 0);         byte\[] data = new byte\[fileinfo.cbSize];         int sizeOfInt32 = Marshal.SizeOf(typeof(int));         IntPtr pRead = Marshal.AllocHGlobal(sizeOfInt32);         pOutStm.Read(data, data.Length, pRead);         int read = Marshal.ReadInt32(pRead);         Marshal.FreeHGlobal(pRead);         return (data.Length);     }


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