Load from Amazon S3 Storage

string key = "sample.docx";
Stream stream = DownloadFile(key);

using (Viewer viewer = new Viewer(stream))
{
    HtmlViewOptions viewOptions = HtmlViewOptions.ForEmbeddedResources();                
    viewer.View(viewOptions);
}

static Stream DownloadFile(string key)
{
    AmazonS3Client client = new AmazonS3Client();
    string bucketName = "my-bucket";
    GetObjectRequest request = new GetObjectRequest
    {
        Key = key,
        BucketName = bucketName
    };
    using (GetObjectResponse response = client.GetObject(request))
    {
        MemoryStream stream = new MemoryStream();
        response.ResponseStream.CopyTo(stream);
        stream.Position = 0;
        return stream;
    }
}