passing filename to DownloadFileCompleted in async file download using webClient C#

Question

My program is using queue to download list of files one by one in a async method using webClient . It looks like this:

    public void DownloadFile()
    {
        if (_downloadUrls.Any())
        {
            var urlAddress = _downloadUrls.Dequeue();
            //Irrelevant code that gets correct URL, and location from queue _downloadUrls

            try
            {
                // Start downloading the file
                webClient1.DownloadFileAsync(URL, location);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
        else
        {
            MessageBox.Show("complete!");
        }
    }

Here is my DownloadFileCompleted code:

private void webClient1_DownloadFileCompleted(object sender, AsyncCompletedEventArgs e)
    {
        if (e.Cancelled == true)
        {
            // MessageBox.Show("Download has been canceled.");
        }
        else
        {
            DownloadFile();
        }
    }

Quesion is how can i pass info about filename to DownloadFileCompleted? I want to change last access date of downloaded files so they woud be the same like on the server and i can only do this in webClient1_DownloadFileCompleted but i don't know which file triggered event DownloadFileCompleted. How can i pass this info to DownloadFileCompleted (preferably as string in parameter).

Answer 1

Use the overload method WebClient.DownloadFileAsync(Uri address, string fileName, object userToken), you can pass the file name as the userToken and then access it in the DownloadFileCompleted handler.

userToken: A user-defined object that is passed to the method invoked when the asynchronous operation completes.

http://msdn.microsoft.com/en-us/library/ms144197(v=vs.110).aspx