So you wire up an event when using WebClient.DownloadFileCompleted. But how do you know which file completed? you may be using a loop to download a bunch of files and to do something specific when each one finishes. The event fired looks like this:
static void myEvent_DownloadFileCompleted(object sender, System.ComponentModel.AsyncCompletedEventArgs e)
both e and sender don’t seem to contain even the name of the file downloaded. What did was, add to the WebClient object’s QueryString property a value which I then look at. See an example below:
static void Main(string[] args)
{
WebClient x = new WebClient();
x.DownloadFileCompleted += new System.ComponentModel.AsyncCompletedEventHandler(myEvent_DownloadFileCompleted);
x.QueryString.Add(“what”, “x”);
x.DownloadFileAsync(new Uri(“http://www.google.com/intl/en_ALL/images/logo.gif”), “c:\\x.gif”);
WebClient y = new WebClient();
y.DownloadFileCompleted += new System.ComponentModel.AsyncCompletedEventHandler(myEvent_DownloadFileCompleted);
y.QueryString.Add(“what”, “y”);
y.DownloadFileAsync(newUri(“http://www.google.com/intl/en_ALL/images/logo.gif”), “c:\\a.gif”);
}
static void myEvent_DownloadFileCompleted(object sender, System.ComponentModel.AsyncCompletedEventArgs e)
{
Console.WriteLine(((System.Net.WebClient)(sender)).QueryString["what"]);
}
