title: WPF Toolkit Chart Does Not Display Data
body: <p>I create WPF app, added chart to markup, made bindings.
  When I add new points to the graph data, axis changes their max values, but graph line doesn't displayed.</p>
  
  <p>I can't understand what is wrong.</p>
  
  <p>Here is markup of my chart:</p>
  
  <pre><code>&lt;chartingToolkit:Chart x:Name="chart" 
                             BorderThickness="1" 
                             VerticalAlignment="Stretch" 
                             Grid.Row="1"&gt;
          &lt;chartingToolkit:LineSeries Title="Options Count" 
                                      Visibility="Visible"
                                      Background="Transparent"
                                      ItemsSource="{Binding MyGraph}"
                                      IndependentValuePath="Key"
                                      DependentValuePath="Value"
                                      DataPointStyle="{StaticResource DataPointStyle1}"
                                      /&gt;
          &lt;chartingToolkit:Chart.Axes&gt;
              &lt;chartingToolkit:LinearAxis Orientation="Y" 
                                          Minimum="0" 
                                          Maximum="{Binding MaxValueForAxis}" 
                                          ShowGridLines="True" /&gt;
  
              &lt;chartingToolkit:DateTimeAxis Orientation="X" 
                                            ShowGridLines="True" 
                                            Minimum="{Binding MinDateForAxis}" 
                                            Maximum="{Binding MaxDateForAxis}" 
                                            IntervalType="Auto" 
                                            AxisLabelStyle="{StaticResource AxisStyle}"/&gt;
          &lt;/chartingToolkit:Chart.Axes&gt;
      &lt;/chartingToolkit:Chart&gt;
  </code></pre>
  
  <p>And ViewModel code that adds values</p>
  
  <pre><code>public void AddNew()
      {
          MyGraph.Add(DateTime.Now.AddDays(i), i * 100);
          i++;
  
          OnPropertyChanged("MyGraph");
          OnPropertyChanged("MaxValueForAxis");
          OnPropertyChanged("MinDateForAxis");
          OnPropertyChanged("MaxDateForAxis");
      }
  </code></pre>
  
  <p>Here is how I set DataContext</p>
  
  <pre><code>ViewModel vm = new ViewModel();
      public MainWindow()
      {
          InitializeComponent();
          DataContext = vm;
      }
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/avfhi.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/avfhi.jpg" alt="enter image description here"></a></p>