Public Function ToJson() As String

public string ToJson()

<Grid x:Name="LayoutRoot" Background="White">
  
  <!-- Add user defined resources for the symbology of the Graphics being drawn in the Map Controls. -->
  <Grid.Resources>
    <esri:SimpleFillSymbol x:Key="BufferSymbol" Fill="#66BB0000" BorderBrush="#88CC0000" BorderThickness="2"  />
    <esri:SimpleRenderer x:Key="PolygonRenderer" Symbol="{StaticResource BufferSymbol}"/>
  </Grid.Resources>
  
  <!-- Add a Map Control with a background ArcGISTiledMapServiceLayer zoomed to North America. There is also
  a placeholder GraphicsLayer that will display Graphics derived from Json based upon a QueryTask that will
  be added when the user clicks the button. -->
  <esri:Map Background="White" HorizontalAlignment="Left" Margin="0,121,0,0" Name="Map1" VerticalAlignment="Top" 
        WrapAround="True" Height="279" Width="600" Extent="-128.75,16.11,-65.00,56.75">
    <esri:ArcGISTiledMapServiceLayer ID="StreetMapLayer" 
          Url="http://services.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer" />
    <esri:GraphicsLayer ID="PolygonLayer" Renderer="{StaticResource PolygonRenderer}"/>
  </esri:Map>
  
  <!--Add a button to perform the work of adding the JSON based Graphics. -->
  <Button Height="23" HorizontalAlignment="Left" Margin="0,92,0,0" Name="Button1" VerticalAlignment="Top" 
          Width="600" Click="Button1_Click" Content="Click the button to draw Graphics derived from Json on the Map"/>
  
  <!-- Provide the instructions on how to use the sample code. -->
  <TextBlock Height="102" HorizontalAlignment="Left" Name="TextBlock1" VerticalAlignment="Top" Width="600" TextWrapping="Wrap"
             Text="Click the button to execute a code-behind function QueryTask against a FeatureLayer in ArcGIS Server. 
             The function loops through the Graphics in the returned FeatureSet and obtains the JSON from the 
             Graphics Geometry. Then new Graphics will be constructed using the Geometry.FromJson method 
             to display in the Map." />
  
</Grid>

private void Button1_Click(object sender, System.Windows.RoutedEventArgs e)
{
  // Create a new QueryTask object that will retrive data from an ArcGIS Server FeatureLayer web service.
  ESRI.ArcGIS.Client.Tasks.QueryTask theQueryTask = new ESRI.ArcGIS.Client.Tasks.QueryTask();
  theQueryTask.Url = "http://server.arcgisonline.com/ArcGIS/rest/services/Demographics/USA_1990-2000_Population_Change/MapServer/4";
  
  // Wire up the QueryTask.ExecutedCompleted Event handler. This code in this event handler will draw Graphics on the Map using the
  // Geometry.ToJson and Geometry.FromJson Methods. 
  theQueryTask.ExecuteCompleted += QueryTask_ExecuteCompleted;
  
  // Wire up the QueryTask.Failed Event handler. This will trap any errors that might occur.
  theQueryTask.Failed += QueryTask_Failed;
  
  // Define a Query for the QueryTask to limit the scope of the FeatureSet returned.
  ESRI.ArcGIS.Client.Tasks.Query theQuery = new ESRI.ArcGIS.Client.Tasks.Query();
  theQuery.Where = "1=1";
  theQuery.ReturnGeometry = true;
  theQuery.ReturnZ = true;
  theQuery.ReturnM = true;
  
  // Execute the Asynchronous QueryTask. This will raise the QueryTask.Executed Completed Event.
  theQueryTask.ExecuteAsync(theQuery);
}
  
private void QueryTask_ExecuteCompleted(object sender, ESRI.ArcGIS.Client.Tasks.QueryEventArgs e)
{
  // Get the FeatureSet from the QueryTaskEventArgs.
  ESRI.ArcGIS.Client.Tasks.FeatureSet theFeatureSet = e.FeatureSet;
  
  // Loop through each returned Graphic in the FeatureSet. 
  foreach (ESRI.ArcGIS.Client.Graphic theGraphic in theFeatureSet)
  {
    // Get the Geometry of the individual Graphic.
    ESRI.ArcGIS.Client.Geometry.Geometry theGeometry = theGraphic.Geometry;
    
    // Test to ensure that we can use the Geometry.ToJson and Geometry.FromJson Methods. 
    if (theGeometry is ESRI.ArcGIS.Client.IJsonSerializable)
    {
      // Get the JSON string from the Geometry of the Graphic.
      string theJsonString = theGraphic.Geometry.ToJson();
      
      // Create a new Geometry object. NOTE: The ESRI.ArcGIS.Client.Geometry.Geometry.FromJson() is a static Method.
      ESRI.ArcGIS.Client.Geometry.Geometry theGeometryFromJson = ESRI.ArcGIS.Client.Geometry.Geometry.FromJson(theJsonString);
      
      // Create a new Graphic with it's Geometry based upon a JSON string.
      ESRI.ArcGIS.Client.Graphic theGraphicFromJson = new ESRI.ArcGIS.Client.Graphic();
      theGraphicFromJson.Geometry = theGeometryFromJson;
      
      // Get the GraphicsLayer that was defined in XAML.
      ESRI.ArcGIS.Client.GraphicsLayer theGraphicsLayer = Map1.Layers["PolygonLayer"] as ESRI.ArcGIS.Client.GraphicsLayer;
      
      // Get the GraphicCollection from the GraphicsLayer.
      ESRI.ArcGIS.Client.GraphicCollection theGraphicsCollection = theGraphicsLayer.Graphics;
      
      // Add the Graphic created from JSON to the GraphicsLayer. The Map will automatically refresh with the new
      // Graphics when the loop is finished processing.
      theGraphicsCollection.Add(theGraphicFromJson);
    }
  }
}
  
private void QueryTask_Failed(object sender, ESRI.ArcGIS.Client.Tasks.TaskFailedEventArgs e)
{
  // If there is a problem with the QueryTask display the error information back to the user. 
  MessageBox.Show(e.Error.ToString());
}

Private Sub Button1_Click(sender As System.Object, e As System.Windows.RoutedEventArgs)
  
  ' Create a new QueryTask object that will retrive data from an ArcGIS Server FeatureLayer web service.
  Dim theQueryTask As ESRI.ArcGIS.Client.Tasks.QueryTask = New ESRI.ArcGIS.Client.Tasks.QueryTask
  theQueryTask.Url = "http://server.arcgisonline.com/ArcGIS/rest/services/Demographics/USA_1990-2000_Population_Change/MapServer/4"
  
  ' Wire up the QueryTask.ExecutedCompleted Event handler. This code in this event handler will draw Graphics on the Map using the
  ' Geometry.ToJson and Geometry.FromJson Methods. 
  AddHandler theQueryTask.ExecuteCompleted, AddressOf QueryTask_ExecuteCompleted
  
  ' Wire up the QueryTask.Failed Event handler. This will trap any errors that might occur.
  AddHandler theQueryTask.Failed, AddressOf QueryTask_Failed
  
  ' Define a Query for the QueryTask to limit the scope of the FeatureSet returned.
  Dim theQuery As ESRI.ArcGIS.Client.Tasks.Query = New ESRI.ArcGIS.Client.Tasks.Query
  theQuery.Where = "1=1"
  theQuery.ReturnGeometry = True
  theQuery.ReturnZ = True
  theQuery.ReturnM = True
  
  ' Execute the Asynchronous QueryTask. This will raise the QueryTask.Executed Completed Event.
  theQueryTask.ExecuteAsync(theQuery)
  
End Sub
  
Private Sub QueryTask_ExecuteCompleted(sender As Object, e As ESRI.ArcGIS.Client.Tasks.QueryEventArgs)
  
  ' Get the FeatureSet from the QueryTaskEventArgs.
  Dim theFeatureSet As ESRI.ArcGIS.Client.Tasks.FeatureSet = e.FeatureSet
  
  ' Loop through each returned Graphic in the FeatureSet. 
  For Each theGraphic As ESRI.ArcGIS.Client.Graphic In theFeatureSet
    
    ' Get the Geometry of the individual Graphic.
    Dim theGeometry As ESRI.ArcGIS.Client.Geometry.Geometry = theGraphic.Geometry
    
    ' Test to ensure that we can use the Geometry.ToJson and Geometry.FromJson Methods. 
    If TypeOf theGeometry Is ESRI.ArcGIS.Client.IJsonSerializable Then
      
      ' Get the JSON string from the Geometry of the Graphic.
      Dim theJsonString As String = theGraphic.Geometry.ToJson
      
      ' Create a new Geometry object. NOTE: The ESRI.ArcGIS.Client.Geometry.Geometry.FromJson() is a Shared Method.
      Dim theGeometryFromJson As ESRI.ArcGIS.Client.Geometry.Geometry = ESRI.ArcGIS.Client.Geometry.Geometry.FromJson(theJsonString)
      
      ' Create a new Graphic with it's Geometry based upon a JSON string.
      Dim theGraphicFromJson As ESRI.ArcGIS.Client.Graphic = New ESRI.ArcGIS.Client.Graphic
      theGraphicFromJson.Geometry = theGeometryFromJson
      
      ' Get the GraphicsLayer that was defined in XAML.
      Dim theGraphicsLayer As ESRI.ArcGIS.Client.GraphicsLayer = TryCast(Map1.Layers("PolygonLayer"), ESRI.ArcGIS.Client.GraphicsLayer)
      
      ' Get the GraphicCollection from the GraphicsLayer.
      Dim theGraphicsCollection As ESRI.ArcGIS.Client.GraphicCollection = theGraphicsLayer.Graphics
      
      ' Add the Graphic created from JSON to the GraphicsLayer. The Map will automatically refresh with the new
      ' Graphics when the loop is finished processing.
      theGraphicsCollection.Add(theGraphicFromJson)
      
    End If
  
  Next theGraphic
  
End Sub
            
Private Sub QueryTask_Failed(sender As Object, e As ESRI.ArcGIS.Client.Tasks.TaskFailedEventArgs)
  
  ' If there is a problem with the QueryTask display the error information back to the user. 
  MessageBox.Show(e.Error.ToString)
  
End Sub