Area and Perimeter

This sample demonstrates using the ArcGIS Runtime SDK for WPF to perform a geometry operation to measure the area and perimeters of specified polygons. To use the sample, click subsequent points on the map to draw a polygon. Double-click to complete the polygon. Once the polygon is completed, its area and perimeter will be calculated and displayed in the upper right corner of the application.

In the code-behind, a LocalGeometryService is started. The url is passed into a GeometryService, which is used to first project the polygon into a spatial reference that uses measured units, and then to calculate the area and perimeter of the polygon.

XAML

<UserControl x:Class="ArcGISWPFSDK.LocalAreasAndLengths"
    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="Transparent">

        <Grid.Resources>
            <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>
            <esri:SimpleFillSymbol x:Key="DefaultFillSymbol" Fill="#7F0000FF" BorderBrush="Blue" BorderThickness="4" />
        </Grid.Resources>

        <esri:Map x:Name="MyMap" Extent="-15000000,2000000,-7000000,8000000" Background="#FFE3E3E3" IsEnabled="False">
            <esri:ArcGISLocalTiledLayer ID="BaseMap" Path="..\\Data\\TPKs\\Topographic.tpk"/>
            <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="Create a polygon by clicking on map. The area and perimeter are displayed here." 
                       Width="200" TextAlignment="Left" Margin="30,20,20,30" TextWrapping="Wrap" Foreground="Black"/>
        </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.Tasks;
using ESRI.ArcGIS.Client.Local;

namespace ArcGISWPFSDK
{
    public partial class LocalAreasAndLengths : UserControl
    {
        private Draw _drawObject;
        GeometryService _geometryTask;

        public LocalAreasAndLengths()
        {
            InitializeComponent();

            LocalGeometryService.GetServiceAsync(localGeometryService =>
            {
                _geometryTask = new GeometryService();
                _geometryTask.Url = localGeometryService.UrlGeometryService;
                _geometryTask.AreasAndLengthsCompleted += GeometryService_AreasAndLengthsCompleted;
                _geometryTask.Failed += GeometryService_Failed;
                MyMap.IsEnabled = true;
            });

            MyMap.Layers.LayersInitialized += (s, e) =>
            {
               _drawObject = new Draw(MyMap)
               {
                   DrawMode = DrawMode.Polygon,
                   IsEnabled = true,
                   FillSymbol = LayoutRoot.Resources["DefaultFillSymbol"] as ESRI.ArcGIS.Client.Symbols.FillSymbol
               };
               _drawObject.DrawComplete += DrawObject_DrawComplete;
               _drawObject.DrawBegin += DrawObject_DrawBegin;
           };
        }

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

        private void DrawObject_DrawComplete(object sender, DrawEventArgs args)
        {
            ESRI.ArcGIS.Client.Geometry.Polygon polygon = args.Geometry as ESRI.ArcGIS.Client.Geometry.Polygon;
            polygon.SpatialReference = MyMap.SpatialReference;
            Graphic graphic = new Graphic()
            {
                Symbol = LayoutRoot.Resources["DefaultFillSymbol"] as ESRI.ArcGIS.Client.Symbols.FillSymbol,
                Geometry = polygon,
            };

            GraphicsLayer graphicsLayer = MyMap.Layers["MyGraphicsLayer"] as GraphicsLayer;
            graphicsLayer.Graphics.Add(graphic);
            
            List<Graphic> graphicList = new List<Graphic>();
            graphicList.Add(graphic);

            _geometryTask.AreasAndLengthsAsync(graphicList);
        }

        private void GeometryService_AreasAndLengthsCompleted(object sender, AreasAndLengthsEventArgs args)
        {
            double miles = args.Results.Lengths[0] * 0.0006213700922;
            double sqmi = Math.Abs(args.Results.Areas[0]) * 0.0000003861003;
            ResponseTextBlock.Text = String.Format("Polygon area: {0} sq. miles\nPolygon perimeter: {1} miles.", Math.Round(sqmi, 3), Math.Round(miles, 3));
        }

        private void GeometryService_Failed(object sender, TaskFailedEventArgs e)
        {
            MessageBox.Show("Geometry Service error: " + e.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
Imports ESRI.ArcGIS.Client.Local

Namespace ArcGISWPFSDK
    Partial Public Class LocalAreasAndLengths
        Inherits UserControl
        Private MyDrawObject As Draw
        Private geometryService As GeometryService

        Public Sub New()
            InitializeComponent()

            Dim localGeometryService As New LocalGeometryService()

            AddHandler localGeometryService.StartCompleted, AddressOf localGeometryService_StartCompleted
            localGeometryService.StartAsync()

            MyDrawObject = New Draw(MyMap) With { _
             .DrawMode = DrawMode.Polygon, _
             .IsEnabled = True, _
             .FillSymbol = TryCast(LayoutRoot.Resources("DefaultFillSymbol"), ESRI.ArcGIS.Client.Symbols.FillSymbol) _
            }
            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 polygon As ESRI.ArcGIS.Client.Geometry.Polygon = TryCast(args.Geometry, ESRI.ArcGIS.Client.Geometry.Polygon)
            polygon.SpatialReference = MyMap.SpatialReference
            Dim graphic As New Graphic() With { _
             .Symbol = TryCast(LayoutRoot.Resources("DefaultFillSymbol"), ESRI.ArcGIS.Client.Symbols.FillSymbol), _
             .Geometry = polygon _
            }

            Dim graphicsLayer As GraphicsLayer = TryCast(MyMap.Layers("MyGraphicsLayer"), GraphicsLayer)
            graphicsLayer.Graphics.Add(graphic)

            Dim graphicList As New List(Of Graphic)()
            graphicList.Add(graphic)

            geometryService.AreasAndLengthsAsync(graphicList)
        End Sub

        Private Sub GeometryService_AreasAndLengthsCompleted(sender As Object, args As AreasAndLengthsEventArgs)

            Dim miles As Double = args.Results.Lengths(0) * 0.0006213700922
            Dim sqmi As Double = Math.Abs(args.Results.Areas(0)) * 0.0000003861003
            ResponseTextBlock.Text = [String].Format("Polygon area: {0} sq. miles" & vbLf & "Polygon perimeter: {1} miles.", Math.Round(sqmi, 3), Math.Round(miles, 3))
        End Sub

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

        Private Sub localGeometryService_StartCompleted(sender As Object, e As ComponentModel.AsyncCompletedEventArgs)
            Dim lgs As LocalGeometryService = TryCast(sender, LocalGeometryService)

            geometryService = New GeometryService()
            geometryService.Url = lgs.UrlGeometryService
            AddHandler geometryService.AreasAndLengthsCompleted, AddressOf GeometryService_AreasAndLengthsCompleted
            AddHandler geometryService.Failed, AddressOf GeometryService_Failed
            MyMap.IsEnabled = True
        End Sub
    End Class
End Namespace