Public Sub ZoomTo( _
   ByVal geom As Geometry _
) 

public void ZoomTo( 
   Geometry geom
)

<!-- 
Add two layers with different extents. By default the Map starts up at the full extent of both layers.  
-->
            
<esri:Map Background="White" HorizontalAlignment="Left" Margin="705,69,0,0" 
          Name="Map3" VerticalAlignment="Top" Height="512" Width="1024">
            
  <esri:ArcGISTiledMapServiceLayer 
        Url="http://services.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer"/>
            
  <!--
  To make the Map's initial Extent start up as the Extent of the second layer (i.e. USA Highways)
  utilize the Initialized event handler.
  -->
  <esri:ArcGISDynamicMapServiceLayer 
        Url="http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StateCityHighway_USA/MapServer" 
        Initialized="ArcGISDynamicMapServiceLayer_Initialized"/>
  
  <!--
  Note: It is not possible to perform the work of the Map1.ZoomTo Method directly in XAML.
  This must be done via code-behind (either C# or VB.NET). Adding the Initialized attribute
  to the XAML allows for use of code-behind.
  -->
</esri:Map>

void MainPage_Loaded(object sender, RoutedEventArgs e)
{
  
  // Clear out any existing layers.
  Map1.Layers.Clear();
  
  // Add an ArcGISTiledMapsServiceLayer to the Map.
  ESRI.ArcGIS.Client.ArcGISTiledMapServiceLayer myArcGISTiledMapServiceLayer = new ESRI.ArcGIS.Client.ArcGISTiledMapServiceLayer();
  myArcGISTiledMapServiceLayer.Url = "http://services.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer";
  Map1.Layers.Add(myArcGISTiledMapServiceLayer);
  
  // Add an ArcGISDynamicServiceLayer to the Map.
  ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer myArcGISDynamicMapServiceLayer = new ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer();
  myArcGISDynamicMapServiceLayer.Url = "http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StateCityHighway_USA/MapServer";
  Map1.Layers.Add(myArcGISDynamicMapServiceLayer);
  
  // By default the Map Control will set its initial extent to the full extent of both layers.
  
  // But if you want to have the initial extent of the Map Control be that of the second layer 
  // (the ArcGISDynamicServiceLayer) then the following line of code will cause that to happen.
  myArcGISDynamicMapServiceLayer.Initialized += new EventHandler<EventArgs>(ArcGISDynamicMapServiceLayer_Initialized);
  
}
  
private void ArcGISDynamicMapServiceLayer_Initialized(object sender, EventArgs e)
{
  
  // The ArcGISDynamicMapServiceLayer.IntialExtent, and Layer.FullExtent can produce different results.
  // Uncomment/comment the two options to suit your preference:
  
  // Option #1: ArcGISDynamicMapServiceLayer.InitialExtent
  if (sender is ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer)
  {
      ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer myArcGISDynamicMapServiceLayer = (ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer)sender;
      Map1.ZoomTo(myArcGISDynamicMapServiceLayer.InitialExtent);
  }
  
  //// Option #2: Layer.FullExtent
  //if (sender is ESRI.ArcGIS.Client.Layer)
  //{
  //    ESRI.ArcGIS.Client.Layer myLayer = (ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer)sender;
  //    Map1.ZoomTo(myLayer.FullExtent);
  //}
  
}

Private Sub MainPage_Loaded(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles Me.Loaded
  
  ' Clear out any existing layers.
  Map1.Layers.Clear()
  
  ' Add an ArcGISTiledMapsServiceLayer to the Map.
  Dim myArcGISTiledMapServiceLayer As New ESRI.ArcGIS.Client.ArcGISTiledMapServiceLayer
  myArcGISTiledMapServiceLayer.Url = "http://services.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer"
  Map1.Layers.Add(myArcGISTiledMapServiceLayer)
  
  ' Add an ArcGISDynamicServiceLayer to the Map.
  Dim myArcGISDynamicMapServiceLayer As New ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer
  myArcGISDynamicMapServiceLayer.Url = "http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StateCityHighway_USA/MapServer"
  Map1.Layers.Add(myArcGISDynamicMapServiceLayer)
  
  ' By default the Map Control will set its initial extent to the full extent of both layers.
  
  ' But if you want to have the initial extent of the Map Control be that of the second layer 
  ' (the ArcGISDynamicServiceLayer) then the following line of code will cause that to happen.
  AddHandler myArcGISDynamicMapServiceLayer.Initialized, AddressOf ArcGISDynamicMapServiceLayer_Initialized
  
  End Sub
  
  Private Sub ArcGISDynamicMapServiceLayer_Initialized(ByVal sender As Object, ByVal e As EventArgs)
  
  ' The ArcGISDynamicMapServiceLayer.IntialExtent, and Layer.FullExtent can produce different results.
  ' Uncomment/comment the two options to suit your preference:
  
  ' Option #1: ArcGISDynamicMapServiceLayer.InitialExtent
  If TypeOf sender Is ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer Then
      Dim myArcGISDynamicMapServiceLayer As ESRI.ArcGIS.Client.ArcGISDynamicMapServiceLayer = sender
      Map1.ZoomTo(myArcGISDynamicMapServiceLayer.InitialExtent)
  End If
  
  '' Option #2: Layer.FullExtent
  'If TypeOf sender Is ESRI.ArcGIS.Client.Layer Then
  '    Dim myLayer As ESRI.ArcGIS.Client.Layer = sender
  '    Map1.ZoomTo(myLayer.FullExtent)
  'End If
  
End Sub