Lengths Online

This sample demonstrates use of a GeometryService to measure distances. To use the sample, click subsequent points on the map to draw a line. Double-click to complete the line. When the line is completed, it's distance will be calculated and displayed in the upper right corner of the application.

In the code-behind, a GeometryService is used to first project the line into a spatial reference that uses measured units, and then to calculate the length of the line.

XAML

<UserControl x:Class="ArcGISWPFSDK.Lengths"
    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:SimpleLineSymbol x:Key="DefaultLineSymbol" Color="Red" Width="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="-118.331,33.7,-116.75,34" >
            <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 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" />
            <TextBlock x:Name="ResponseTextBlock" Text="Create a polyline by clicking on the map. The distance is displayed here." 
                       Width="200" TextAlignment="Left" Margin="30,20,30,30" TextWrapping="Wrap" Foreground="Black" />
        </Grid>

    </Grid>
</UserControl>

C#

using System;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using ESRI.ArcGIS.Client;
using ESRI.ArcGIS.Client.Tasks;

namespace ArcGISWPFSDK
{
    public partial class Lengths : UserControl
    {
        private Draw MyDrawObject;

        public Lengths()
        {
            InitializeComponent();
            MyDrawObject = new Draw(MyMap)
            {
                DrawMode = DrawMode.Polyline,
                IsEnabled = true,
                LineSymbol = LayoutRoot.Resources["DefaultLineSymbol"] as ESRI.ArcGIS.Client.Symbols.LineSymbol
            };
            MyDrawObject.DrawComplete += MyDrawObject_DrawComplete;
            MyDrawObject.DrawBegin += MyDrawObject_DrawBegin;
        }

        private void MyDrawObject_DrawBegin(object sender, EventArgs args)
        {
            GraphicsLayer graphicsLayer = MyMap.Layers["MyGraphicsLayer"] as GraphicsLayer;
            graphicsLayer.ClearGraphics();
        }

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

            GeometryService geometryService =
                            new GeometryService("http://tasks.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer");
            geometryService.LengthsCompleted += GeometryService_LengthsCompleted;
            geometryService.Failed += GeometryService_Failed;

            GraphicsLayer graphicsLayer = MyMap.Layers["MyGraphicsLayer"] as GraphicsLayer;
            graphicsLayer.Graphics.Add(graphic);
            geometryService.LengthsAsync(graphicsLayer.Graphics.ToList(), LinearUnit.SurveyMile, CalculationType.Geodesic, null);
        }

        private void GeometryService_LengthsCompleted(object sender, ESRI.ArcGIS.Client.Tasks.LengthsEventArgs args)
        {
            ResponseTextBlock.Text =
                String.Format("The distance of the polyline is {0} miles", Math.Round(args.Results[0], 3));
        }

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

VB.NET

Imports System.Linq
Imports System.Windows
Imports System.Windows.Controls
Imports ESRI.ArcGIS.Client
Imports ESRI.ArcGIS.Client.Tasks

Namespace ArcGISWPFSDK
    Partial Public Class Lengths
        Inherits UserControl
        Private MyDrawObject As Draw

        Public Sub New()
            InitializeComponent()
            MyDrawObject = New Draw(MyMap) With { _
             .DrawMode = DrawMode.Polyline, _
             .IsEnabled = True, _
             .LineSymbol = TryCast(LayoutRoot.Resources("DefaultLineSymbol"), ESRI.ArcGIS.Client.Symbols.LineSymbol) _
            }
            AddHandler MyDrawObject.DrawComplete, AddressOf MyDrawObject_DrawComplete
            AddHandler MyDrawObject.DrawBegin, AddressOf MyDrawObject_DrawBegin
        End Sub

        Private Sub MyDrawObject_DrawBegin(sender As Object, args As EventArgs)
            Dim graphicsLayer As GraphicsLayer = TryCast(MyMap.Layers("MyGraphicsLayer"), GraphicsLayer)
            graphicsLayer.ClearGraphics()
        End Sub

        Private Sub MyDrawObject_DrawComplete(sender As Object, args As DrawEventArgs)
            Dim polyline As ESRI.ArcGIS.Client.Geometry.Polyline = TryCast(args.Geometry, ESRI.ArcGIS.Client.Geometry.Polyline)
            polyline.SpatialReference = MyMap.SpatialReference
            Dim graphic As New Graphic() With { _
             .Symbol = TryCast(LayoutRoot.Resources("DefaultLineSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol), _
             .Geometry = polyline _
            }

            Dim geometryService As New GeometryService("http://tasks.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer")
            AddHandler geometryService.LengthsCompleted, AddressOf GeometryService_LengthsCompleted
            AddHandler geometryService.Failed, AddressOf GeometryService_Failed

            Dim graphicsLayer As GraphicsLayer = TryCast(MyMap.Layers("MyGraphicsLayer"), GraphicsLayer)
            graphicsLayer.Graphics.Add(graphic)
            geometryService.LengthsAsync(graphicsLayer.Graphics.ToList(), LinearUnit.SurveyMile, CalculationType.Geodesic, Nothing)
        End Sub

        Private Sub GeometryService_LengthsCompleted(sender As Object, args As ESRI.ArcGIS.Client.Tasks.LengthsEventArgs)
            ResponseTextBlock.Text = [String].Format("The distance of the polyline is {0} miles", Math.Round(args.Results(0), 3))
        End Sub

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