Multi Threaded File Downloader Using Proxy c#

My开发者_如何学编程 goal is to create a class that gets a link and download it to local drive. The program should support downloading from http\https\ftp links and moreover in my work i have a dedicated proxy(with no authentication) for it. the main system is downloader over asp.net which each student can request a file to download. all the files are pretty big files from 50MB to unlimited size so it should be a fast downloader.

this is my currentcode:

public void DownloadLink(string link)
    {
        string filename ;
        try
        {
            WebClient wc = new WebClient();
            Uri downloadLink= new Uri(link);
            wc.DownloadFileCompleted += new AsyncCompletedEventHandler(DownloadFileCompleted);
            filename = link.Substring(link.LastIndexOf("/") + 1);
            Console.WriteLine("Downloading File" + filename);
            wc.DownloadFileAsync(downloadLink, filename);
        }
        catch (Exception i)
        {
            System.Console.WriteLine ("Failed" + i.ToString());
        }

    }

    private void DownloadFileCompleted(object sender, AsyncCompletedEventArgs e)
    {
        Console.WriteLine("Download Completed");
    }

here are my questions: 1.How can implement simultaneous downloads? 2.how to set the Webclient with my proxy? 3 Does the WebClient.DownloadAsync supports https&ftp or should i handle it? 4. Is there a way to implement the download to be faster? 5.I saw few implementations that included HttpWebRequest,HttpWebResponse & Streams. does it has better preformance?

---

1 How can implement simultaneous downloads?

You could spawn a task for each download - have a look at the Task Parallel Library (TPL). Make sure that you don't over saturate your internet connection. Spawning too many download threads actually can have a detrimental effect on throughput.

2 how to set the Webclient with my proxy?

You have to set the Proxy property.

3 Does the WebClient.DownloadAsync supports https&ftp or should i handle it?

This shouldn't have to do anything with Async or not -

Ftp: Yes, there are examples here

Https: Yes, there's a clarification here

4 Is there a way to implement the download to be faster?

I doubt that using WebRequest / streams directly will gain you anything, most of the time cost comes from actually transferring the data to the local machine.