title: Bing Maps - Auto update location binding of pushpins
body: <p>I'm using the Bing Maps control to display a series of custom pushpins, representing objects which are constantly moving around and changing state.</p>
  
  <p>Using databinding the various properties for the objects are being updated as they should, but for some reason this doesn't apply to their locations.</p>
  
  <p>I have the map bound to an ObservableCollection as such:</p>
  
  <pre><code>&lt;UserControl.Resources&gt;    
      &lt;DataTemplate x:Key="PushpinTemplate"&gt;
          &lt;v:CustomPushpin /&gt;
      &lt;/DataTemplate&gt;
  &lt;/UserControl.Resources&gt;
  </code></pre>
  
  <p>...</p>
  
  <pre><code>&lt;m:Map Name="map"&gt;
     &lt;m:MapItemsControl ItemTemplate="{StaticResource PushpinTemplate}" ItemsSource="{Binding Objects}" /&gt;
  &lt;/m:Map&gt;
  </code></pre>
  
  <p>...and in CustomPushpin:</p>
  
  <pre><code>&lt;UserControl
  ...    
     m:MapLayer.Position="{Binding Location}" m:MapLayer.PositionOrigin="BottomCenter"
     mc:Ignorable="d" d:DesignHeight="126" d:DesignWidth="85"&gt;
  </code></pre>
  
  <p>Like all other properties, the Location of the individual objects are implemented using INotifyPropertyChanged.</p>
  
  <pre><code>private Location _location;
  public Location Location
  {
     get { return _location; }
     set { _location = value; OnPropertyChanged("Location"); }
  }
  </code></pre>
  
  <p>When the map is moving, either because of panning or zooming, the objects move, but othersize not.</p>
  
  <p>I can't quite figure if I'm doing something wrong here, or if it's a problem with the Bing Maps control.</p>
  
  <p>Any thought?</p>