ストリーム(IStream)のシーク位置を先頭へ戻す

    // shlwapi.dll version 5.0 or later 互換

    // CStreamHelper::Emulete_IStream_Reset()と同等

    static HRESULT Emulete_IStream_Reset(IStream *pstm)

    {

        if (pstm == NULL)

        {

            return E_FAIL;

        }

        HRESULT hr = S_OK;

        try

        {

            LARGE_INTEGER zeroPos = {0, 0};

            ULARGE_INTEGER streamSize = {0, 0};

            hr = pstm->Seek(zeroPos, STREAM_SEEK_SET, &streamSize);

            if (FAILED(hr))

            {

                return hr;

            }

        }

        catch (...)

        {

            return E_FAIL;

        }

        return hr;

    }