Distance Online

This sample demonstrates using an ESRI.ArcGIS.Client.Tasks GeometryService that takes an input graphic polyline and point and returns the linear difference of the shortest length between the two graphics.

To use the sample, click on the map to add a polyline then add a point. After the point is entered the shortest distance between them is displayed in the textblock on the map.

XAML

<UserControl x:Class="ArcGISWPFSDK.Distance"
    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">

        <Grid.Resources>
            <esri:SimpleMarkerSymbol x:Key="DefaultMarkerSymbol" Size="6">
                <esri:SimpleMarkerSymbol.Color>
                    <RadialGradientBrush>
                        <GradientStop Color="#FFFF0000" Offset="0.578"/>
                        <GradientStop Color="#FF0E0D07" Offset="1"/>
                    </RadialGradientBrush>
                </esri:SimpleMarkerSymbol.Color>
            </esri:SimpleMarkerSymbol>
            <esri:SimpleLineSymbol x:Key="DefaultLineSymbol" Width="2" Color="Red" />
            <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="-112.461447, 33.393199, -111.564157, 33.66974" >
            <esri:ArcGISTiledMapServiceLayer ID="StreetMapLayer" 
                      Url="http://services.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer"/>
            <esri:GraphicsLayer ID="MyGraphicsLayer" />
        </esri:Map>

        <Grid HorizontalAlignment="Right" VerticalAlignment="Top" Margin="0,10,10,0" >
            <Rectangle Fill="{StaticResource PanelGradient}" Stroke="Gray"  RadiusX="10" RadiusY="10" 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" />
            <TextBlock x:Name="ResponseTextBlock" Text="Click on the map to add a polyline, then add a point.  After the point is entered the shortest distance between them is displayed here." 
                       Width="200" TextAlignment="Left" Margin="30,20,30,30" TextWrapping="Wrap" Foreground="Black" />
        </Grid>

    </Grid>
</UserControl>

C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using ESRI.ArcGIS.Client;
using ESRI.ArcGIS.Client.Tasks;
using ESRI.ArcGIS.Client.Geometry;

namespace ArcGISWPFSDK
{
    public partial class Distance : UserControl
    {
        private Draw MyDrawObject;
        GraphicsLayer graphicsLayer;

        public Distance()
        {
            InitializeComponent();

            graphicsLayer = MyMap.Layers["MyGraphicsLayer"] as GraphicsLayer;

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

        private void MyDrawObject_DrawBegin(object sender, EventArgs args)
        {
            if (graphicsLayer.Graphics.Count >= 2)
                graphicsLayer.ClearGraphics();
        }

        private void MyDrawObject_DrawComplete(object sender, DrawEventArgs args)
        {
            //ESRI.ArcGIS.Client.Geometry.Polyline polyline = args.Geometry as ESRI.ArcGIS.Client.Geometry.Polyline;
            args.Geometry.SpatialReference = MyMap.SpatialReference;
            Graphic graphic = new Graphic() { Geometry = args.Geometry };
            if (args.Geometry is Polyline)
                graphic.Symbol = LayoutRoot.Resources["DefaultLineSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol;
            else
                graphic.Symbol = LayoutRoot.Resources["DefaultMarkerSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol;

            graphicsLayer.Graphics.Add(graphic);

            if (graphicsLayer.Graphics.Count == 1)
                MyDrawObject.DrawMode = DrawMode.Point;
            else if (graphicsLayer.Graphics.Count == 2)
            {
                MyDrawObject.IsEnabled = false;
                GeometryService geometryService =
                            new GeometryService("http://tasks.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer");
                geometryService.DistanceCompleted += GeometryService_DistanceCompleted;
                geometryService.Failed += GeometryService_Failed;

                MyDrawObject.DrawMode = DrawMode.Polyline;

                DistanceParameters distanceParameters = new DistanceParameters()
                {
                    DistanceUnit = LinearUnit.SurveyMile,
                    Geodesic = true
                };

                geometryService.DistanceAsync(graphicsLayer.Graphics[0].Geometry, graphicsLayer.Graphics[1].Geometry, distanceParameters);
                ResponseTextBlock.Text = "The distance between geometries is... ";
            }
        }

        void GeometryService_DistanceCompleted(object sender, DistanceEventArgs e)
        {
            ResponseTextBlock.Text =
                String.Format("The distance between geometries is {0} miles", Math.Round(e.Distance, 3));
            MyDrawObject.IsEnabled = true;
        }

        private void GeometryService_Failed(object sender, TaskFailedEventArgs e)
        {
            MessageBox.Show("Geometry Service error: " + e.Error);
            MyDrawObject.IsEnabled = true;
        }
    }
}

VB.NET

Imports System.Collections.Generic
Imports System.Linq
Imports System.Net
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Documents
Imports System.Windows.Input
Imports System.Windows.Media
Imports System.Windows.Media.Animation
Imports ESRI.ArcGIS.Client
Imports ESRI.ArcGIS.Client.Tasks
Imports ESRI.ArcGIS.Client.Geometry

Namespace ArcGISWPFSDK
    Partial Public Class Distance
        Inherits UserControl
        Private MyDrawObject As Draw
        Private graphicsLayer As GraphicsLayer

        Public Sub New()
            InitializeComponent()

            graphicsLayer = TryCast(MyMap.Layers("MyGraphicsLayer"), GraphicsLayer)

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

        Private Sub MyDrawObject_DrawBegin(sender As Object, args As EventArgs)
            If graphicsLayer.Graphics.Count >= 2 Then
                graphicsLayer.ClearGraphics()
            End If
        End Sub

        Private Sub MyDrawObject_DrawComplete(sender As Object, args As DrawEventArgs)
            'ESRI.ArcGIS.Client.Geometry.Polyline polyline = args.Geometry as ESRI.ArcGIS.Client.Geometry.Polyline;
            args.Geometry.SpatialReference = MyMap.SpatialReference
            Dim graphic As New Graphic() With { _
             .Geometry = args.Geometry _
            }
            If TypeOf args.Geometry Is Polyline Then
                graphic.Symbol = TryCast(LayoutRoot.Resources("DefaultLineSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol)
            Else
                graphic.Symbol = TryCast(LayoutRoot.Resources("DefaultMarkerSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol)
            End If

            graphicsLayer.Graphics.Add(graphic)

            If graphicsLayer.Graphics.Count = 1 Then
                MyDrawObject.DrawMode = DrawMode.Point
            ElseIf graphicsLayer.Graphics.Count = 2 Then
                MyDrawObject.IsEnabled = False
                Dim geometryService As New GeometryService("http://tasks.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer")
                AddHandler geometryService.DistanceCompleted, AddressOf GeometryService_DistanceCompleted
                AddHandler geometryService.Failed, AddressOf GeometryService_Failed

                MyDrawObject.DrawMode = DrawMode.Polyline

                Dim distanceParameters As New DistanceParameters() With { _
                 .DistanceUnit = LinearUnit.SurveyMile, _
                 .Geodesic = True _
                }

                geometryService.DistanceAsync(graphicsLayer.Graphics(0).Geometry, graphicsLayer.Graphics(1).Geometry, distanceParameters)
                ResponseTextBlock.Text = "The distance between geometries is... "
            End If
        End Sub

        Private Sub GeometryService_DistanceCompleted(sender As Object, e As DistanceEventArgs)
            ResponseTextBlock.Text = [String].Format("The distance between geometries is {0} miles", Math.Round(e.Distance, 3))
            MyDrawObject.IsEnabled = True
        End Sub

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