get timeline of 2 (or more) users from Twitter

I am trying to get the timeline of 2 or more users in a list, and then order by the date and display in a listview

at the moment I have the following :-

        Contacts searchTerm1 = cmbContact.SelectedItem as Contacts;

        if (searchTerm1 != null)
        {
            contactList = GetCurrentContacts(searchTerm1.CatID);

            foreach (var contact in contactList)
            {
                GetTweetResults(contact.Username);

                foreach (var contactTweet in _contactTweets)
                {
                    _allContactTweets.Add(contactTweet);
                }

            }

            TweetList1.ItemsSource = _allContactTweets;
        }

And I am getting the tweets Async

    private void GetTweetResults(string user)
    {

        WebClient twitterAccess = new WebClient();
        twitterAccess.DownloadStringCompleted += new DownloadStringCompletedEventHandler(twitterAccess_DownloadStringCompleted);
        twitterAccess.DownloadStringAsync(new Uri("http://api.twitter.com/1/statuses/user_timeline.xml?screen_name=" + user));

    }

    private void twitterAccess_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs args)
    {
        try
        {
            XElement xmlTweets = XElement.Parse(args.Result);
            var contactTweets = (from tweet in xmlTweets.Descendants("status")
                                                    select new ContactTweet
                                                               {
                                                                   ProfileImage =
                                                                       tweet.Element("user").Element("profile_image_url").Value,
                                                                   TweetText = tweet.Element("text").Value,
                                                                   UserName = tweet.Element("user").Element("screen_name").Value,
                                                                   Created = (tweet.Element("created_at").Value.ParseDateTime())
                                                               }).ToList();


            foreach (var contactTweet in contactTweets)
            {
                _contactTweets.Add(contactTweet);
            }


        }
        catch (Exception exception)
        {
            MessageBox.Show("Error downloading tweets - " + exception.Message);
        }

    }
}

Now my idea is, in GetTweetResults, to wait for the twitterAccess_DownloadStringCompleted to finish and then continue the process, however I do not know how to do it.

Can anyone tell me how to achieve this?

Thanks for your help and time

UPDATE

Managed to get it down to

        WebClient twitterAccess = new WebClient();
        twitterAccess.DownloadStringCompleted += new DownloadStringCompletedEventHandler(twitterAccess_DownloadStringCompleted);
        twitterAccess.DownloadStringAsync(new Uri("http://api.twitter.com/1/statuses/user_timeline.xml?screen_name=" + contactList1[0].Username));

        WebClient twitterAccess2 = new WebClient();
        twitterAccess2.DownloadStringCompleted += new DownloadStringCompletedEventHandler(twitterAccess_DownloadStringCompleted);
        twitterAccess2.DownloadStringAsync(new Uri("http://api.twitter.com/1/statuses/user_timeline.xml?screen_name=" + contactList1[1].Username));

Now i need to find a way to loop in the contact开发者_Python百科List1 and generate the WebClient dynamically.....

UPDATE 2

Problem solved

        foreach (var contact in contactList)
        {
            WebClient twitterAccess = new WebClient();
            twitterAccess.DownloadStringCompleted += new DownloadStringCompletedEventHandler(twitterAccess_DownloadStringCompleted);

            twitterAccess.DownloadStringAsync(new Uri("http://api.twitter.com/1/statuses/user_timeline.xml?screen_name=" + contact.Username));
        }

---

foreach (var contact in contactList) { WebClient twitterAccess = new WebClient(); twitterAccess.DownloadStringCompleted += new DownloadStringCompletedEventHandler(twitterAccess_DownloadStringCompleted);

        twitterAccess.DownloadStringAsync(new Uri("http://api.twitter.com/1/statuses/user_timeline.xml?screen_name=" + contact.Username));
    }