How to use the WebClient.DownloadDataAsync() method in this context?

Question

My plan is to have a user write down a movie title in my program and my program will pull the appropiate information asynchronously so the UI doesn\'t freeze up.

Her

Answer 1

You need to handle the DownloadDataCompleted event:

static void Main()
{
    string url = "http://google.com";
    WebClient client = new WebClient();
    client.DownloadDataCompleted += DownloadDataCompleted;
    client.DownloadDataAsync(new Uri(url));
    Console.ReadLine();
}

static void DownloadDataCompleted(object sender,
    DownloadDataCompletedEventArgs e)
{
    byte[] raw = e.Result;
    Console.WriteLine(raw.Length + " bytes received");
}

The args contains other bits of information relating to error conditions etc - check those too.

Also note that you'll be coming into DownloadDataCompleted on a different thread; if you are in a UI (winform, wpf, etc) you'll need to get to the UI thread before updating the UI. From winforms, use this.Invoke. For WPF, look at the Dispatcher.