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stgopenstorage (ole32)

C# Signature:

/// <summary>Opens a compound document file and represents it as an IStorage object</summary>
/// <remarks>Use on Windows 2000 and earlier</remarks>
/// <param name="pwcsName">The path and filename of the file to open</param>
/// <param name="pstgPriority">Generally passed as null</param>
/// <param name="grfMode">Access Method</param>
/// <param name="snbExclude">Must be NULL</param>
/// <param name="reserved">Pass as zero (0)</param>
/// <param name="ppstgOpen">out IStorage</param>
/// <returns>int HRESULT</returns>
/// Needs more help form MS
static extern int StgOpenStorage(
    [MarshalAs(UnmanagedType.LPWStr)] string pwcsName
    , IStorage pstgPriority
    , STGM grfMode                // Access Method (uint)
    , IntPtr snbExclude            // Must be NULL
    , uint reserved                // Reserved
    , out IStorage ppstgOpen);    // Returned Storage

///PreserveSig set to false automatically converts HRESULTS values to exceptions.
///Note the return value is void not an int (HRESULT).
[DllImport("ole32.dll", PreserveSig = false)]
static extern void StgOpenStorage([MarshalAs(UnmanagedType.LPWStr)] string pwcsName,
IStorage pstgPriority, STGM grfMode, IntPtr snbExclude, uint reserved,
out IStorage ppstgOpen);

User-Defined Types:



Win2K and later should use the StgOpenStorageEx function.

Tips & Tricks:

Please add some!

Sample Code:

string pathAndFilename = @"C:\outlookmail.msg"
IStorage storage;
int hResult = StgOpenStorage(pathAndFilename, null, STGM.READ_ONLY, IntPtr.Zero, 0, out storage);
// Then one can use the EnumElements method of the IStorage interface to enum the properties of the OLE2 storage.

Alternative Managed API:

See StgOpenStorageEx for an example of using the System.IO.Packaging classes to access OLE structured storage.


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