h1. Creating Torrents

[[Creating Torrents#Example-1|Example 1]] shows how to create a simple torrent.
[[Creating Torrents#Example-2|Example 2]] shows how to create a torrent asynchronously so that it does not block the main thread in your application.
[[Creating Torrents#Example-3|Example 3]] shows how to abort the creation of a torrent after it has started
[[Creating Torrents#Example-4|Example 4]] shows how to create a torrent and load it without having to hash the data a second time

h2. Example 1

<pre><code class="java">
        // 'path' is the location of the file/folder which is going to be converted
        // to a torrent. 'savePath' is where the .torrent file will be saved.
        void CreateTorrent(string path, string savePath)
        {
            // The class used for creating the torrent
            TorrentCreator c = new TorrentCreator();
            
            // Add one tier which contains two trackers
            List<string> tier = new List<string>();
            tier.Add("http://www.example.com/announce");
            tier.Add("http://backup.example.com/announce");
            
            c.Announces.Add(tier);
            c.Comment = "This is the comment";
            c.CreatedBy = "Alan using " + VersionInfo.ClientVersion;
            c.Publisher = "www.homepage.com";

            // Set the torrent as private so it will not use DHT or peer exchange
            // Generally you will not want to set this.
            c.Private = true;

            // Path can be either a directory *or* a file.
            c.Path = path;

            // Every time a piece has been hashed, this event will fire. It is an
            // asynchronous event, so you have to handle threading yourself.
            c.Hashed += delegate (object o, TorrentCreatorEventArgs e) {
                Console.WriteLine("Current File is {0}% hashed", e.FileCompletion);
                Console.WriteLine("Overall {0}% hashed", e.OverallCompletion);
                Console.WriteLine("Total data to hash: {0}", e.OverallSize);
            };

            // Create the torrent file and save it directly to the specified path
            // Different overloads of 'Create' can be used to save the data to a Stream
            // or just return it as a BEncodedDictionary (its native format) so it can be
            // processed in memory
            c.Create(save_path);
        }
</code></pre>

h2. Example 2

<pre><code class="java">
        // 'path' is the location of the file/folder which is going to be converted
        // to a torrent. 'savePath' is where the .torrent file will be saved.
        void CreateTorrent(string path, string savePath)
        {
            // The class used for creating the torrent
            TorrentCreator c = new TorrentCreator();

            // Fill in the path, trackers as in Example 1
            FillInStandardInformation(c);

            // Create the torrent asynchronously
            c.BeginCreate(c, TorrentCreated);
        }

        void TorrentCreated(IAsyncResult result)
        {
            TorrentCreator c = (TorrentCreator)result.AsyncState;

            // If any errors occured while creating the torrent, they
            // will be rethrown here.
            try
            {   
                // Open the destination file and use the EndCreate overload which
                // writes the data directly to the Stream. 
                using (FileStream stream = File.OpenWrite(savePath))
                    c.EndCreate(result, stream);
            }
            catch (Exception ex)
            {
                Console.WriteLine("Error creating torrent: {0}", ex);
            }
        }
</code></pre>


h2. Example 3

<pre><code class="java">
        // 'path' is the location of the file/folder which is going to be converted
        // to a torrent. 'savePath' is where the .torrent file will be saved.
        void CreateTorrent(string path, string savePath)
        {
            // The class used for creating the torrent
            TorrentCreator c = new TorrentCreator();

            // Fill in the path, trackers as in Example 1
            FillInStandardInformation(c);

            // Create the torrent asynchronously and keep a reference to the
            // IAsyncResult it returns
            TorrentCreatorAsyncResult result = c.BeginCreate(c, TorrentCreated);

            // Abort creation of the torrent (can be called at any stage). Note, you
            // can only abort the creation if the torrent is created asynchronously
            result.Abort();
        }
</code></pre>


h2. Example 4

<pre><code class="java">
public static void CreateAndLoadTorrent (ClientEngine engine)
{
    // Instantiate a torrent creator
    TorrentCreator creator = new TorrentCreator ();

    // Create a TorrentFileSource which is used to populate the .torrent
    ITorrentFileSource files = new TorrentFileSource ("somefile.dat");

    // Create the Torrent metadata blob
    BEncodedDictionary torrentDict = creator.Create (files);

    // Instantiate a torrent
    Torrent torrent = Torrent.Load (torrentDict);

    // Create a fake fast resume data with all the pieces set to true so we
    // don't have to hash the torrent when adding it directly to the engine.
    BitField bitfield = new BitField (torrent.Pieces.Count).Not ();
    FastResume fastResumeData = new FastResume(torrent.InfoHash, bitfield);

    // Create a TorrentManager so the torrent can be downloaded and load
    // the FastResume data so we don't have to hash it again.
    TorrentManager manager = new TorrentManager (torrent, "SavePath", new TorrentSettings ());
    manager.LoadFastResume (fastResumeData);

    // Register it with the engine and start the download
    engine.Register (manager);
    engine.StartAll ();
}
</code></pre>