internal static extern int StgOpenStorageEx(
string pwcsName,
[MarshalAs(UnmanagedType.U4)] NativeMethods.STGM grfMode,
[MarshalAs(UnmanagedType.U4)] NativeMethods.STGFMT stgfmt,
[MarshalAs(UnmanagedType.U4)] int grfAttrs,
IntPtr pStgOptions,
IntPtr reserved2,
ref Guid riid,
out NativeMethods.IStorage ppObjectOpen);
private static void ExtractSubStorage(string databaseFile, string storageName, string extractFile)
{
IStorage storage;
NativeMethods.STGM openMode = NativeMethods.STGM.READ | NativeMethods.STGM.SHARE_DENY_WRITE;
int hr = NativeMethods.StgOpenStorage(databaseFile, IntPtr.Zero, (uint)openMode, IntPtr.Zero, 0, out storage);
if (hr != 0)
{
Marshal.ThrowExceptionForHR(hr);
}
try
{
openMode = NativeMethods.STGM.READ | NativeMethods.STGM.SHARE_EXCLUSIVE;
IStorage subStorage = storage.OpenStorage(storageName, IntPtr.Zero, (uint)openMode, IntPtr.Zero, 0);
try
{
IStorage newStorage;
openMode = NativeMethods.STGM.CREATE | NativeMethods.STGM.READWRITE | NativeMethods.STGM.SHARE_EXCLUSIVE;
hr = NativeMethods.StgCreateDocfile(extractFile, (uint)openMode, 0, out newStorage);
if (hr != 0)
{
Marshal.ThrowExceptionForHR(hr);
}
try
{
subStorage.CopyTo(0, IntPtr.Zero, IntPtr.Zero, newStorage);
newStorage.Commit(0);
}
finally
{
Marshal.ReleaseComObject(newStorage);
}
}
finally
{
Marshal.ReleaseComObject(subStorage);
}
}
finally
{
Marshal.ReleaseComObject(storage);
}
}