Relation Online

This sample demonstrates use of a GeometryService to calculate topological relationships. To use the sample, click points on the map and click Execute. The relationship of the points to the pre-defined polygons on the map is calculated and added to the points' MapTips.

In the code-behind, a GeometryService is used to check whether the points are in the polygons by specifying a relation parameter of esriGeometryRelationWithin. The results are added to the points' MapTips when the are returned.

XAML

<UserControl x:Class="ArcGISWPFSDK.Relation"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    xmlns:esri="http://schemas.esri.com/arcgis/client/2009">
    <Grid x:Name="LayoutRoot" Background="White">
        <Grid.Resources>
            <esri:PictureMarkerSymbol x:Key="DefaultPointMarkerSymbol" OffsetX="0" OffsetY="23" Source="/Assets/Images/flag-red-24x24.png" />
            <esri:SimpleFillSymbol x:Key="DefaultPolygonFillSymbol" Fill="#660000FF" BorderBrush="Blue" BorderThickness="4" />
            <LinearGradientBrush x:Key="PanelGradient" EndPoint="0.5,1" StartPoint="0.5,0">
                <LinearGradientBrush.RelativeTransform>
                    <TransformGroup>
                        <ScaleTransform CenterY="0.5" CenterX="0.5"/>
                        <SkewTransform CenterY="0.5" CenterX="0.5"/>
                        <RotateTransform Angle="176" CenterY="0.5" CenterX="0.5"/>
                        <TranslateTransform/>
                    </TransformGroup>
                </LinearGradientBrush.RelativeTransform>
                <GradientStop Color="#FF145787" Offset="0.16"/>
                <GradientStop Color="#FF3D7FAC" Offset="0.502"/>
                <GradientStop Color="#FF88C5EF" Offset="0.984"/>
            </LinearGradientBrush>
        </Grid.Resources>

        <esri:Map x:Name="MyMap" Extent="-118,32,-116,35">
            <esri:Map.Layers>

                <esri:ArcGISTiledMapServiceLayer ID="StreetMapLayer" 
                      Url="http://services.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer" />

                <esri:GraphicsLayer ID="MyPolygonGraphicsLayer">
                    <esri:GraphicsLayer.Graphics >
                        <esri:Graphic x:Name="Graphic0" Symbol="{StaticResource DefaultPolygonFillSymbol}">
                            <esri:Polygon x:Name="Polygon_0">
                                <esri:Polygon.Rings>
                                    <esri:PointCollection>-117,33 -116.5,33 -116.5,34 -117,34 -117,33</esri:PointCollection>
                                </esri:Polygon.Rings>
                            </esri:Polygon>
                        </esri:Graphic>
                        <esri:Graphic x:Name="Graphic1" Symbol="{StaticResource DefaultPolygonFillSymbol}">
                            <esri:Polygon x:Name="Polygon_1">
                                <esri:Polygon.Rings>
                                    <esri:PointCollection>-118,34 -117.5,34 -117.5,35 -118,35 -118,34</esri:PointCollection>
                                </esri:Polygon.Rings>
                            </esri:Polygon>
                        </esri:Graphic>
                        <esri:Graphic x:Name="Graphic2" Symbol="{StaticResource DefaultPolygonFillSymbol}">
                            <esri:Polygon x:Name="Polygon_2">
                                <esri:Polygon.Rings>
                                    <esri:PointCollection>-116,32 -117,32 -117,33.5 -116,33.5 -116,32</esri:PointCollection>
                                </esri:Polygon.Rings>
                            </esri:Polygon>
                        </esri:Graphic>
                        <esri:Graphic x:Name="Graphic3" Symbol="{StaticResource DefaultPolygonFillSymbol}">
                            <esri:Polygon x:Name="Polygon_3">
                                <esri:Polygon.Rings>
                                    <esri:PointCollection>-115,31 -115.5,31 -115.5,32 -115,32 -115,31</esri:PointCollection>
                                </esri:Polygon.Rings>
                            </esri:Polygon>
                        </esri:Graphic>
                    </esri:GraphicsLayer.Graphics>
                    <esri:GraphicsLayer.MapTip>
                        <Grid Background="LightYellow">
                            <StackPanel Orientation="Vertical" Margin="5">
                                <TextBlock Text="{Binding [Name]}" HorizontalAlignment="Left" Foreground="Black" />
                                <TextBlock Text="{Binding [Relation]}" HorizontalAlignment="Left" Foreground="Black"/>
                            </StackPanel>
                            <Border BorderBrush="Black" BorderThickness="1" />
                        </Grid>
                    </esri:GraphicsLayer.MapTip>
                </esri:GraphicsLayer>

                <esri:GraphicsLayer ID="MyPointGraphicsLayer">
                    <esri:GraphicsLayer.MapTip>
                        <Grid Background="LightYellow">
                            <StackPanel Orientation="Vertical" Margin="5">
                                <TextBlock Text="{Binding [Name]}" HorizontalAlignment="Left" Foreground="Black"/>
                                <TextBlock Text="{Binding [Relation]}" HorizontalAlignment="Left" Foreground="Black" />
                            </StackPanel>
                            <Border BorderBrush="Black" BorderThickness="1" />
                        </Grid>
                    </esri:GraphicsLayer.MapTip>
                </esri:GraphicsLayer>

            </esri:Map.Layers>
        </esri:Map>

        <Grid HorizontalAlignment="Right" VerticalAlignment="Top" Margin="0,15,15,0" >
            <Rectangle Stroke="Gray"  RadiusX="10" RadiusY="10" Fill="{StaticResource PanelGradient}" Margin="0,0,0,5" >
                <Rectangle.Effect>
                    <DropShadowEffect/>
                </Rectangle.Effect>
            </Rectangle>
            <Rectangle Fill="#FFFFFFFF" Stroke="DarkGray" RadiusX="5" RadiusY="5" Margin="10,10,10,15" />
            <StackPanel Orientation="Vertical" HorizontalAlignment="Center" Margin="30,20,30,30" >
                <TextBlock x:Name="InformationText" Width="200" Foreground="Black" Text="Add points by clicking on map.  Click Execute to compute the relation between the points and the polygons. The results will be displayed by hovering over the polygons or markers." TextAlignment="Left"  TextWrapping="Wrap" />
                <Button x:Name="ExecuteRelationButton" Content="Execute" Click="ExecuteRelationButton_Click" Width="100" Visibility="Visible" Margin="0,5,0,0"/>
            </StackPanel>
        </Grid>

    </Grid>
</UserControl>

C#

using System;
using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
using ESRI.ArcGIS.Client;
using ESRI.ArcGIS.Client.Geometry;
using ESRI.ArcGIS.Client.Tasks;

namespace ArcGISWPFSDK
{
    public partial class Relation : UserControl
    {
        private Draw MyDrawObject;
        private GraphicsLayer polygonLayer;
        private GraphicsLayer pointLayer;
        private GeometryService geometryService;

        public Relation()
        {
            InitializeComponent();

            polygonLayer = MyMap.Layers["MyPolygonGraphicsLayer"] as GraphicsLayer;
            MyMap.Layers.LayersInitialized += Layers_LayersInitialized;
            pointLayer = MyMap.Layers["MyPointGraphicsLayer"] as GraphicsLayer;

            MyDrawObject = new Draw(MyMap)
            {
                DrawMode = DrawMode.Point,
                IsEnabled = true,
            };
            MyDrawObject.DrawComplete += MyDrawObject_DrawComplete;
        }

        void Layers_LayersInitialized(object sender, EventArgs args)
        {
            for (int i = 0; i < polygonLayer.Graphics.Count; i++)
            {
                Graphic graphic = polygonLayer.Graphics[i];
                graphic.Geometry.SpatialReference = MyMap.SpatialReference;
                if (!graphic.Attributes.ContainsKey("Name"))
                {
                    graphic.Attributes.Add("Name", String.Format("Polygon_{0}", i));
                    graphic.Attributes.Add("Relation", null);
                }
            }
        }

        private void MyDrawObject_DrawComplete(object sender, DrawEventArgs args)
        {
            MyDrawObject.IsEnabled = false;

            string name = String.Format("Point_{0}", pointLayer.Graphics.Count);

            MapPoint mapPoint = args.Geometry as MapPoint;

            Graphic graphic = new Graphic()
            {
                Symbol = LayoutRoot.Resources["DefaultPointMarkerSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol,
                Geometry = mapPoint
            };

            graphic.Attributes.Add("Name", name);
            graphic.Attributes.Add("Relation", null);

            pointLayer.Graphics.Add(graphic);

            MyDrawObject.IsEnabled = true;
        }

        private void ExecuteRelationButton_Click(object sender, RoutedEventArgs e)
        {
            MyDrawObject.IsEnabled = false;
            ExecuteRelationButton.Visibility = Visibility.Collapsed;

            geometryService =
            new GeometryService("http://tasks.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer");
            geometryService.RelationCompleted += GeometryService_RelationCompleted;
            geometryService.SimplifyCompleted += GeometryService_SimplifyCompleted;
            geometryService.Failed += GeometryService_Failed;

            if (pointLayer.Graphics.Count < 1)
            {
                MessageBox.Show("No points available");
                MyDrawObject.IsEnabled = true;
                ExecuteRelationButton.Visibility = Visibility.Visible;
                return;
            }

            foreach (Graphic graphic in pointLayer.Graphics)
                graphic.Attributes["Relation"] = null;

            foreach (Graphic graphic in polygonLayer.Graphics)
                graphic.Attributes["Relation"] = null;

            // Call simplify operation to correct orientation of rings in a polygon (clockwise = ring, counterclockwise = hole)
            geometryService.SimplifyAsync(polygonLayer.Graphics);
        }

        void GeometryService_SimplifyCompleted(object sender, GraphicsEventArgs e)
        {
            geometryService.RelationAsync(
              pointLayer.Graphics,
              e.Results,
              GeometryRelation.esriGeometryRelationWithin, null);
        }

        private void GeometryService_RelationCompleted(object sender, RelationEventArgs args)
        {
            List<GeometryRelationPair> results = args.Results;
            foreach (GeometryRelationPair pair in results)
            {
                if (pointLayer.Graphics[pair.Graphic1Index].Attributes["Relation"] == null)
                {
                    pointLayer.Graphics[pair.Graphic1Index].Attributes["Relation"] =
                    string.Format("Within Polygon {0}", pair.Graphic2Index);
                }
                else
                {
                    pointLayer.Graphics[pair.Graphic1Index].Attributes["Relation"] +=
                    "," + pair.Graphic2Index.ToString();
                }

                if (polygonLayer.Graphics[pair.Graphic2Index].Attributes["Relation"] == null)
                {
                    polygonLayer.Graphics[pair.Graphic2Index].Attributes["Relation"] =
                    string.Format("Contains Point {0}", pair.Graphic1Index);
                }
                else
                {
                    polygonLayer.Graphics[pair.Graphic2Index].Attributes["Relation"] +=
                    "," + pair.Graphic1Index.ToString();
                }
            }

            ExecuteRelationButton.Visibility = Visibility.Visible;
            MyDrawObject.IsEnabled = true;
        }

        private void GeometryService_Failed(object sender, TaskFailedEventArgs args)
        {
            MessageBox.Show("Geometry Service error: " + args.Error);
        }
    }
}

VB.NET

Imports System.Collections.Generic
Imports System.Windows
Imports System.Windows.Controls
Imports ESRI.ArcGIS.Client
Imports ESRI.ArcGIS.Client.Geometry
Imports ESRI.ArcGIS.Client.Tasks

Namespace ArcGISWPFSDK
    Partial Public Class Relation
        Inherits UserControl
        Private MyDrawObject As Draw
        Private polygonLayer As GraphicsLayer
        Private pointLayer As GraphicsLayer
        Private geometryService As GeometryService

        Public Sub New()
            InitializeComponent()

            polygonLayer = TryCast(MyMap.Layers("MyPolygonGraphicsLayer"), GraphicsLayer)
            AddHandler MyMap.Layers.LayersInitialized, AddressOf Layers_LayersInitialized
            pointLayer = TryCast(MyMap.Layers("MyPointGraphicsLayer"), GraphicsLayer)

            MyDrawObject = New Draw(MyMap) With { _
             .DrawMode = DrawMode.Point, _
             .IsEnabled = True _
            }
            AddHandler MyDrawObject.DrawComplete, AddressOf MyDrawObject_DrawComplete
        End Sub

        Private Sub Layers_LayersInitialized(sender As Object, args As EventArgs)
            For i As Integer = 0 To polygonLayer.Graphics.Count - 1
                Dim graphic As Graphic = polygonLayer.Graphics(i)
                graphic.Geometry.SpatialReference = MyMap.SpatialReference
                If Not graphic.Attributes.ContainsKey("Name") Then
                    graphic.Attributes.Add("Name", [String].Format("Polygon_{0}", i))
                    graphic.Attributes.Add("Relation", Nothing)
                End If
            Next
        End Sub

        Private Sub MyDrawObject_DrawComplete(sender As Object, args As DrawEventArgs)
            MyDrawObject.IsEnabled = False

            Dim name As String = [String].Format("Point_{0}", pointLayer.Graphics.Count)

            Dim mapPoint As MapPoint = TryCast(args.Geometry, MapPoint)

            Dim graphic As New Graphic() With { _
             .Symbol = TryCast(LayoutRoot.Resources("DefaultPointMarkerSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol), _
             .Geometry = mapPoint _
            }

            graphic.Attributes.Add("Name", name)
            graphic.Attributes.Add("Relation", Nothing)

            pointLayer.Graphics.Add(graphic)

            MyDrawObject.IsEnabled = True
        End Sub

        Private Sub ExecuteRelationButton_Click(sender As Object, e As RoutedEventArgs)
            MyDrawObject.IsEnabled = False
            ExecuteRelationButton.Visibility = Visibility.Collapsed

            geometryService = New GeometryService("http://tasks.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer")
            AddHandler geometryService.RelationCompleted, AddressOf GeometryService_RelationCompleted
            AddHandler geometryService.SimplifyCompleted, AddressOf GeometryService_SimplifyCompleted
            AddHandler geometryService.Failed, AddressOf GeometryService_Failed

            If pointLayer.Graphics.Count < 1 Then
                MessageBox.Show("No points available")
                MyDrawObject.IsEnabled = True
                ExecuteRelationButton.Visibility = Visibility.Visible
                Return
            End If

            For Each graphic As Graphic In pointLayer.Graphics
                graphic.Attributes("Relation") = Nothing
            Next

            For Each graphic As Graphic In polygonLayer.Graphics
                graphic.Attributes("Relation") = Nothing
            Next

            ' Call simplify operation to correct orientation of rings in a polygon (clockwise = ring, counterclockwise = hole)
            geometryService.SimplifyAsync(polygonLayer.Graphics)
        End Sub

        Private Sub GeometryService_SimplifyCompleted(sender As Object, e As GraphicsEventArgs)
            geometryService.RelationAsync(pointLayer.Graphics, e.Results, GeometryRelation.esriGeometryRelationWithin, Nothing)
        End Sub

        Private Sub GeometryService_RelationCompleted(sender As Object, args As RelationEventArgs)
            Dim results As List(Of GeometryRelationPair) = args.Results
            For Each pair As GeometryRelationPair In results
                If pointLayer.Graphics(pair.Graphic1Index).Attributes("Relation") Is Nothing Then
                    pointLayer.Graphics(pair.Graphic1Index).Attributes("Relation") = String.Format("Within Polygon {0}", pair.Graphic2Index)
                Else
                    pointLayer.Graphics(pair.Graphic1Index).Attributes("Relation") += "," & pair.Graphic2Index.ToString()
                End If

                If polygonLayer.Graphics(pair.Graphic2Index).Attributes("Relation") Is Nothing Then
                    polygonLayer.Graphics(pair.Graphic2Index).Attributes("Relation") = String.Format("Contains Point {0}", pair.Graphic1Index)
                Else
                    polygonLayer.Graphics(pair.Graphic2Index).Attributes("Relation") += "," & pair.Graphic1Index.ToString()
                End If
            Next

            ExecuteRelationButton.Visibility = Visibility.Visible
            MyDrawObject.IsEnabled = True
        End Sub

        Private Sub GeometryService_Failed(sender As Object, args As TaskFailedEventArgs)
            MessageBox.Show("Geometry Service error: " & Convert.ToString(args.[Error]))
        End Sub
    End Class
End Namespace