C#DownloaderClass

public class Downloader {

    public bool Finished = false;
    public double TotalBytes = 0;
    public double BytesRecieved = 0;

    // Percent stuff
    public float Progress { get { return ((float)Progress_Percent) / 100.0f; } }
    public int Progress_Percent = 0;

    private WebClient client;

    private string _url;
    private string _location;

    public void Start(string url, string location)
    {
        Finished = false;

        _url = url;
        _location = location;

        // Setup the client
        client = new WebClient();
        client.DownloadProgressChanged += client_DownloadProgressChanged;
        client.DownloadFileCompleted += client_DownloadFileCompleted;

        // Start the download
        client.DownloadFileAsync(new Uri(url), location);
    }

    public void Unzip()
    {
        // Unzips the file we downloaded
        if (Finished)
        {
            // If Finished
            string fileName = Path.GetFileName(_location);

            if (fileName.Contains(".zip"))
            {
                // It's a zip file we downloaded.

                // Begin unzipping it.
                Progress_Percent = 0;
                Finished = false;

                int totalFiles = 0;

                using (ZipFile zip = ZipFile.Read(_location))
                {
                    try
                    {
                        totalFiles = zip.Entries.Count;

                        if (totalFiles <= 0) { totalFiles = 1; }

                        for (int i = 0; i < zip.Count; i++)
                        {
                            ZipEntry e = zip[i];

                            e.Extract(Path.GetDirectoryName(_location), ExtractExistingFileAction.OverwriteSilently);

                            Progress_Percent = (int)((double)i / (double)zip.Count);
                        }
                    }
                    catch (Exception z) { Debug.Log(z.ToString()); }
                }

                try
                {
                    // Delete the zip
                    File.Delete(_location);
                }
                catch (Exception z) { }
                    
                Finished = true;
                Progress_Percent = 100;
            }
        }
    }

    void client_DownloadFileCompleted(object sender, System.ComponentModel.AsyncCompletedEventArgs e)
    {
        Finished = true;
    }

    void client_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
    {
        Progress_Percent = e.ProgressPercentage;
        TotalBytes = e.TotalBytesToReceive;
        BytesRecieved = e.BytesReceived;
    }
}