Question

I have ComboBox that takes data from another class

public partial class MainWindow : Window
{
      private ObservableCollection<MyDataClass> _myList = new ObservableCollection<MyDataClass>();

      public MainWindow()
      {
           InitializeComponent();
           comboBox1.DataContext = _myList;
      }

      private void Button_Click(object sender, EventArgs e)
      {
           _myList = AnotherClass.SomeMethod();
      }
}

The only way to update ComboBox data after button click is to implement INotifyPropertyChanged interface in MyDataClass or there are another ways to do that? I look for another way because MyDataClass is generated from web-service so I need to create some adapter class to implement INotifyPropertyChanged

Answer 1

public partial class MainWindow : Window, INotifyPropertyChanged
{
      private ObservableCollection<MyDataClass> m_myList;
      public ObservableCollection<MyDataClass> _myList
      {
         get
         {
             return m_myList;
         }
         set
         {
             m_myList = value;
             RaisePropertyChanged("_myList");
         }
      }

      public MainWindow()
      {
           InitializeComponent();
           _myList = new ObservableCollection<MyDataClass>();
           comboBox1.DataContext = _myList;
      }

      private void Button_Click(object sender, EventArgs e)
      {
           _myList = AnotherClass.SomeMethod();
      }

      public event PropertyChangedEventHandler PropertyChanged;
      public void RaisePropertyChanged(String _Prop)
      {
          if (PropertyChanged != null)
          {
              this.PropertyChanged(this, new PropertyChangedEventArgs(_Prop));
          }
      }
}

This is because you’re actually assigning a value to a property, you’re not updating the ObservableCollection.
Thus it needs to be treated as a property, and you have to implement INotifyPropertyChanged.

And by the way, WCF DataContracts automatically implement INotifyPropertyChanged.