On this blog I will show how to create a simple WPF application that connects to Facebook. In this sample it is assumed that you already acquired an Application ID from Facebook. If not please check this link http://developers.facebook.com/docs/. The Application ID is one of the requirements to connect to Facebook.
To begin, download the Facebook toolkit from the this link http://facebooktoolkit.codeplex.com/
In you WPF application reference the following dlls:
- Facebook.dll
Create the following class in your application:
/// <summary> /// /// </summary> public static class FacebookService { private static DesktopSession _Session; /// <summary> /// /// </summary> public static DesktopSession Session { get { return _Session; } set { _Session = value; } } private static BindingManager _Service; /// <summary> /// /// </summary> public static BindingManager Service { get { return _Service; } set { _Service = value; } } /// <summary> /// /// </summary> /// <param name="session"></param> public static void Init(DesktopSession session) { _Session = session; _Service = BindingManager.CreateInstance(_Session); } }
The DesktopSession is a Facebook component from the toolkit that manage the connection and authentication to Facebook. To know more on how Facebook authenticates you application, check this link http://wiki.developers.facebook.com/index.php/How_Facebook_Authenticates_Your_Application
The BindingManager is another Facebook component that is reponsible retrieving friends list, photos and other information stored in a user’s profile.
To make this work, add the following code from the constructor of your WPF window:
/// <summary> /// Interaction logic for MainWindow.xaml /// </summary> public partial class MainWindow : Window { private FacebookModel _vm; /// <summary> /// /// </summary> public MainWindow() { DesktopSession session = new DesktopSession("cd0ade267315e76b6e9d0b5855df7e98", true); session.Login(); FacebookService.Init(session); InitializeComponent(); _vm = new FacebookModel(); Loaded += new RoutedEventHandler(MainWindow_Loaded); Closing += new System.ComponentModel.CancelEventHandler(MainWindow_Closing); }
From the above code we use the DesktopSession to authenticate our applicatio to Facebook, when launching this application WPF will automatically redirects the application to a Facebook login page then returns back to our main window.
The following code shows the Facebook View Model that facilitates the retrieval of data from Facebook.
using Facebook.BindingHelper; using System; using System.Collections.ObjectModel; using System.ComponentModel; namespace MyFacebook.MainApplication.Model { /// <summary> /// /// </summary> public class FacebookModel : INotifyPropertyChanged { /// <summary> /// /// </summary> public FacebookModel() { _Friends = FacebookService.Service.Friends; _Friends.DataRetrievalCompletedEvent += new System.EventHandler<DataRetrievalCompletedEventArgs>(Friends_DataRetrievalCompletedEvent); _Activities = FacebookService.Service.Stream; _Activities.DataRetrievalCompletedEvent += new System.EventHandler<DataRetrievalCompletedEventArgs>(Activities_DataRetrievalCompletedEvent); long user_id = FacebookService.Service.CurrentUserId; _CurrentUserList = FacebookService.Service.GetUsers(new long[] { user_id }); _CurrentUserList.DataRetrievalCompletedEvent += new System.EventHandler<DataRetrievalCompletedEventArgs>(CurrentUser_DataRetrievalCompletedEvent); } #region Current User private FacebookContactCollection _CurrentUserList; private FacebookContact _CurrentUser; /// <summary> /// /// </summary> public FacebookContact CurrentUser { get { return _CurrentUser; } set { if (_CurrentUser != value) { _CurrentUser = value; OnPropertyChanged("CurrentUser"); } } } /// <summary> /// /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void CurrentUser_DataRetrievalCompletedEvent(object sender, DataRetrievalCompletedEventArgs e) { _CurrentUserList = sender as FacebookContactCollection; if (_CurrentUserList != null && _CurrentUserList.Count > 0) { CurrentUser = _CurrentUserList[0]; } } #endregion #region Activities private ActivityPostCollection _Activities; /// <summary> /// /// </summary> public ActivityPostCollection Activities { get { return _Activities; } set { if (_Activities != value) { _Activities = value; OnPropertyChanged("Activities"); } } } /// <summary> /// /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void Activities_DataRetrievalCompletedEvent(object sender, DataRetrievalCompletedEventArgs e) { } #endregion #region Selected Friend private FacebookContact _SelectedFriend; /// <summary> /// /// </summary> public FacebookContact SelectedFriend { get { return _SelectedFriend; } set { if (_SelectedFriend != value) { _SelectedFriend = value; SelectedFriendPhotos = _SelectedFriend.PhotosBy; OnPropertyChanged("SelectedFriend"); } } } private FacebookPhotoCollection _SelectedFriendPhotos; /// <summary> /// /// </summary> public FacebookPhotoCollection SelectedFriendPhotos { get { return _SelectedFriendPhotos; } set { if (_SelectedFriendPhotos != value) { _SelectedFriendPhotos = value; OnPropertyChanged("SelectedFriendPhotos"); } } } #endregion #region Friends private FacebookContactCollection _Friends; /// <summary> /// /// </summary> public FacebookContactCollection Friends { get { return _Friends; } set { if (_Friends != value) { _Friends = value; OnPropertyChanged("Friends"); } } } /// <summary> /// /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void Friends_DataRetrievalCompletedEvent(object sender, DataRetrievalCompletedEventArgs e) { } #endregion /// <summary> /// /// </summary> public event PropertyChangedEventHandler PropertyChanged; /// <summary> /// /// </summary> /// <param name="propertyName"></param> private void OnPropertyChanged(string propertyName) { if (PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); } } } }
That’s it!
