DownloadFileAsync, классы и вывод состояний

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Net;

namespace Downloader
{
    public partial class Form1 : Form
    {
        AsyncDown d;
        public Form1()
        {
            InitializeComponent();
        }
        private void button1_Click(object sender, EventArgs e)
        {
            d = new AsyncDown(progressBar1, "http://ссылка", @"сохранение");   
        }
    }       

    public class AsyncDown
    {
        private WebClient webClient;
        private ProgressBar progressBar;      
        private long state;
        private long total;
        public AsyncDown( string url, string path)
        {
            webClient = new WebClient();
            StartDownload(url, path);
        }
        public AsyncDown(ProgressBar pBar, string url, string path)
        {
            webClient = new WebClient();
            progressBar = pBar;
            StartDownload(url, path);
        }
        
        public void StartDownload(string url, string path)
        {
            webClient.DownloadFileCompleted += new AsyncCompletedEventHandler(Completed);
            webClient.DownloadProgressChanged += new DownloadProgressChangedEventHandler(ProgressChanged);
            webClient.DownloadFileAsync(new Uri(url), path);
        }
        public void ProgressChanged(object sender, DownloadProgressChangedEventArgs e)
        {
            progressBar.Value = e.ProgressPercentage;     
            state = e.BytesReceived;
            total = e.TotalBytesToReceive; 
        }
        private void Completed(object sender, AsyncCompletedEventArgs e)
        {
        }
    }
}