Load an image into a PictureBox on a different thread

I am trying to load a picture that is fetched on-demand from Google's Static Maps based against a (UK) Post Code.

Lets say I have a client and the clients has an address. One of the properties of client is PostCode. I have a form that loads clients. I feed the client ID to this form's constructor and then use LINQ 2 SQL to load all sorts of information including an address.

private void LoadBranchDetails() {
  Text_Update_BI_Name.Text = Branch.BranchNumber;
  Text_Update_BI_Manager.Text = String.Format("{0} {1}", Branch.PharmacyManager.FirstName, Branch.PharmacyManager.LastName);
  DropDownList_Update_BI_Coordinator.SelectedValue = Branch.CoordinatorID;
  DropDownList_Update_BI_ComputerSystem.SelectedValue = Branch.ComputerSystemID;
  Text_Update_BI_Phone.Text = Branch.PhoneNumber;
  Text_Update_BI_Fax.Text = Branch.FaxNumber;

  Address BranchAddress = Branch.Contact.Addresses.FirstOrDefault();
  Text_Update_AI_House.Text = BranchAddress.HouseNumber;
  Text_Update_AI_Street.Text = BranchAddress.Street;
  Text_Update_AI_Area.Text = BranchAddress.Area;
  Text_Update_AI_Post.Text = BranchAddress.PostCode;
  DropDownList_Update_AI_City.SelectedValue = BranchAddress.City.OID;

  MaskedText_Update_OI_NoPharmacist.Value = Branch.NumberOfPharmacists;
  MaskedText_Update_OI_NoDispensers.Value = Branch.NumberOfDispensers;
  MaskedText_Update_OI_NoMonFri.Value = Branch.NumberOfItemsMondayToFriday;
  MaskedText_Update_OI_NoSat.Value = Branch.NumberOfItemsSaturday;
  MaskedText_Update_OI_NoSun.Value = Branch.NumberOfItemsSunday;
  MaskedText_Update_OI_NoAddicts.Value = Branch.NumberOfAddicts;
  MaskedText_Update_OI_NoSupervised.Value = Branch.Supervised;
  MaskedText_Update_OI_NoUnsupervised.Value = Branch.Unsupervised;

  Check_Update_OI_ConfRoom.Checked = Branch.ConsultationRoom;

  try {        
    PictureGoogleMaps.Image = GoogleAddressInfo.FetchMapInfo(Text_Update_AI_Post.Text).GoogleStaticMap;

  } catch (Exception) {
    PictureGoogleMaps.Image = Resources.DefaultGoogleMap;

  }
}

The line that loads the image into the PictureGoogleMaps causes a hang in UI as the ".GoogleStaticMap" property generates the Google static image when called.

Upon searching the internet, i found this helpful example:

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();

        // Declare a list开发者_StackOverflow中文版 of URLs and their respective picture boxes
        var items = new Dictionary<string, PictureBox> 
        { 
            { "http://www.google.com/logos/spring09.gif", new PictureBox() { Top = 0, Width = 300, Height = 80  } }, 
            { "http://www.google.com/logos/stpatricks_d4gwinner_eo09.gif", new PictureBox() { Top = 100, Width = 300, Height = 80 } },
            { "http://www.google.com/logos/schiaparelli09.gif", new PictureBox() { Top = 200, Width = 300, Height = 80 } },
            { "http://www.google.com/logos/drseuss09.gif", new PictureBox() { Top = 300, Width = 300, Height = 80 } },
            { "http://www.google.com/logos/valentines09.gif", new PictureBox() { Top = 400, Width = 300, Height = 80 } },
            { "http://www.google.com/logos/unix1234567890.gif", new PictureBox() { Top = 500, Width = 300, Height = 80 } },
            { "http://www.google.com/logos/charlesdarwin_09.gif", new PictureBox() { Top = 600, Width = 300, Height = 80 } },
        };

        foreach (var item in items)
        {
            var worker = new BackgroundWorker();
            worker.DoWork += (o, e) =>
            {
                // This function will be run on a background thread
                // spawned from the thread pool.
                using (var client = new WebClient())
                {
                    var pair = (KeyValuePair<string, PictureBox>)e.Argument;
                    e.Result = new KeyValuePair<PictureBox, byte[]>(pair.Value, client.DownloadData(pair.Key));
                }
            };
            worker.RunWorkerCompleted += (o, e) => 
            {
                // This function will be run on the main GUI thread
                var pair = (KeyValuePair<PictureBox, byte[]>)e.Result;
                using (var stream = new MemoryStream(pair.Value))
                {
                    pair.Key.Image = new Bitmap(stream);
                }
                Controls.Add(pair.Key);
            };
            worker.RunWorkerAsync(item);
        }
    }
}

Now I just need to figure out how to remove the for loop and use this in my scenario. Any ideas?

The sample code comes from this link.

Thanks.

public partial class Form1 : Form
    {        
        private BackgroundWorker imageLoader;

        public Form1()
        {
            InitializeComponent();

            this.imageLoader = new BackgroundWorker();
            this.imageLoader.DoWork += HandleOnImageLoaderDoWork;
            this.imageLoader.RunWorkerCompleted += HandleImageLoaderOnRunWorkerCompleted;

            this.LoadUserDetails(1);
        }

        private void LoadUserDetails(Int32 userID)
        {
            this.imageLoader.RunWorkerAsync(userID.ToString());
            // get the user details
            // populate the UI controls with the data....
        }

        private void HandleImageLoaderOnRunWorkerCompleted(Object sender, RunWorkerCompletedEventArgs e)
        {
            this.pictureBox1.Image = (Image)e.Result;
        }

        private void HandleOnImageLoaderDoWork(Object sender, DoWorkEventArgs e)
        {
            // simulate a web request for an image;
            Thread.Sleep(3000);
            Image image = Image.FromFile(@"test.jpg");
            e.Result = image;
        }
    }

Also make sure that you show some UI notification that a background operation is in process...something like a initial image (loading.gif) in the PictureBox.

Is it that hard to remove the foreach loop? You only need to load a single picture so remove the foreach loop and pass the url of the picture and the target picturebox to the backgroundworker.