title: DataVisualization.Charting chart is not working with ObservableList
body: <p>I'm trying to couple <code>System.Windows.Controls.DataVisualization.Charting</code> chart with some <code>ObservableCollection</code>.</p>
  
  <p>I created class for one data point:</p>
  
  <pre><code>public class ChartDataPoint : INotifyPropertyChanged
  {
      private double xvalue;
  
      public double XValue
      {
          get { return xvalue; }
          set {
              if (xvalue != value)
              { 
                  xvalue = value;
                  NotifyPropertyChanged("XValue");
              }
          }
      }
  
      private double yvalue;
  
      public double YValue
      {
          get { return yvalue; }
          set {
              if (yvalue != value)
              {
                  yvalue = value;
                  NotifyPropertyChanged("YValue");
              }
          }
      }
  
      /// &lt;summary&gt;
      /// Constructor
      /// &lt;/summary&gt;
      /// &lt;param name="x"&gt;&lt;/param&gt;
      /// &lt;param name="y"&gt;&lt;/param&gt;
      private ChartDataPoint(double x, double y)
      {
          this.XValue = x;
          this.YValue = y;
      }
  
      public static ChartDataPoint CreateNew(double x, double y)
      {
          return new ChartDataPoint(x, y);
      }
  
      public event PropertyChangedEventHandler PropertyChanged;
  
      protected void NotifyPropertyChanged(String info)
      {
          if (PropertyChanged != null)
          {
              PropertyChanged(this, new PropertyChangedEventArgs(info));
          }
      }
  }
  </code></pre>
  
  <p>Then I created <code>ObservableCollection&lt;ChartDataPoint&gt;</code>.</p>
  
  <pre><code>public MainWindow()
  {
      InitializeComponent();
      ListSeries1Data.CollectionChanged += ListSeries1Data_CollectionChanged;
      Chart1.DataContext = ListSeries1Data;
  }
  </code></pre>
  
  <p>After my window shows up I'm clicking a button that adds item to my list:</p>
  
  <pre><code>private void Button_Click(object sender, RoutedEventArgs e)
      {
          ListSeries1Data.Add(ChartDataPoint.CreateNew(i, r.Next(100)));
          i++;
      }
  </code></pre>
  
  <p>And this is part of my XAML with this chart.</p>
  
  <pre><code> &lt;c:Chart Name="Chart1" Background="WhiteSmoke"&gt;
          &lt;c:LineSeries Name="Series1" 
                        Title="Read value"
                        IndependentValueBinding="{Binding Path=XValue}"
                        DependentValueBinding="{Binding Path=YValue}"&gt;
          &lt;/c:LineSeries&gt;
  &lt;/c:Chart&gt;
  </code></pre>
  
  <p>What is wrong with my code?</p>