using(var session = new Session())
{
    // Make the session listen on a port in the range
    // 6881-6889
    session.ListenOn(6881, 6889);

    // Create the AddTorrentParams with info about the torrent
    // we'd like to add.
    var addParams = new AddTorrentParams
    {
        SavePath = "C:\\Downloads",
        Url = "<url to a torrent file>"
    };

    // Add a torrent to the session and get a `TorrentHandle`
    // in return.
    var handle = session.AddTorrent(addParams);

    while(true)
    {
        // Get a `TorrentStatus` instance from the handle.
        var status = handle.QueryStatus();

        // If we are seeding, our job here is done.
        if(status.IsSeeding)
        {
            break;
        }

        // Print our progress and sleep for a bit.
        Console.WriteLine("{0}% downloaded", status.Progress * 100);
        Thread.Sleep(1000);
    }
}