Generalize Online

This sample demonstrates using an ESRI.ArcGIS.Client.Tasks GeometryService that takes graphic polyline with numerous vertices and returns a generalized polyline with less vertices. Additionally a SliderControl appears after the GeometryService completes that allows adjusting the opacity of the generalized polyline graphics layer for ease of viewing.

To use the sample, click the Generalize Line button to generalize the line feature. Original line and vertices are red. Generalized line a vertices are cyan. Use the slider to change the opacity of the generalized line. Zoom in on the graphics to see in better detail the difference between the original polyline and the generalized line.

XAML

<UserControl x:Class="ArcGISWPFSDK.Generalize"
    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" Color="Red" Size="6" />
            <esri:SimpleMarkerSymbol x:Key="NewMarkerSymbol" Color="#FF00FFFF" Size="6" />
            <esri:SimpleLineSymbol x:Key="DefaultLineSymbol" Color="#AAFF0000" Width="2" />
            <esri:SimpleLineSymbol x:Key="NewLineSymbol" Color="#AA00FFFF" Width="2"/>
            <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="-12000000,3000000,-7000000,7000000">
            <esri:ArcGISTiledMapServiceLayer ID="StreetMapLayer" 
                      Url="http://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer"/>
            <esri:GraphicsLayer ID="OriginalLineGraphicsLayer" />
            <esri:GraphicsLayer ID="GeneralizedLineGraphicsLayer" />
        </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" />
            <StackPanel Orientation="Vertical" Margin="30,20,20,30" >
                <TextBlock x:Name="ResponseTextBlock" Text="Click the Generalize Line button to generalize the line feature.  Original line and vertices are red.  Generalized line a vertices are cyan.  Use the slider to change the opacity of the generalized line." 
                           Width="400" TextAlignment="Left"  TextWrapping="Wrap" />
                <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" >
                    <Button Content="Generalize Line" Margin="0,5,5,0" x:Name="GeneralizeButton" 
                             Click="GeneralizeButton_Click" IsEnabled="False" />
                </StackPanel>
                <StackPanel x:Name="SliderStackPanel" Margin="5,5,5,5" Orientation="Horizontal" 
                                HorizontalAlignment="Center" Visibility="Collapsed" >
                    <TextBlock FontSize="9" Foreground="Black" Text="0" />
                    <Slider x:Name="GeneralizeLayersOpacity" Minimum="0" Maximum="1" SmallChange="0.01" 
                                LargeChange="0.1" Value="0.75" Orientation="Horizontal" 
                                ValueChanged="GeneralizeLayerOpacity_ValueChanged" Width="120" />
                    <TextBlock FontSize="9" Foreground="Black" Text="100" />
                </StackPanel>
            </StackPanel>
        </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 ESRI.ArcGIS.Client.Tasks;
using ESRI.ArcGIS.Client;
using ESRI.ArcGIS.Client.Geometry;

namespace ArcGISWPFSDK
{
    public partial class Generalize : UserControl
    {
        GraphicsLayer originalGraphicsLayer;

        public Generalize()
        {
            InitializeComponent();
            MyMap.Layers.LayersInitialized += Layers_LayersInitialized;

            originalGraphicsLayer = MyMap.Layers["OriginalLineGraphicsLayer"] as GraphicsLayer;
        }

        void Layers_LayersInitialized(object sender, EventArgs args)
        {
            if (originalGraphicsLayer != null && originalGraphicsLayer.Graphics.Count == 0)
            {
                QueryTask queryTask =
                    new QueryTask("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StatesCitiesRivers_USA/MapServer/1");
                Query query = new Query();
                query.ReturnGeometry = true;
                query.OutSpatialReference = MyMap.SpatialReference;
                query.Where = "NAME = 'Mississippi'";

                queryTask.ExecuteCompleted += queryTask_ExecuteCompleted;
                queryTask.Failed += queryTask_Failed;
                queryTask.ExecuteAsync(query, query.OutSpatialReference);
            }
        }

        void queryTask_Failed(object sender, TaskFailedEventArgs e)
        {
            MessageBox.Show("Query error: " + e.Error);
        }

        void queryTask_ExecuteCompleted(object sender, QueryEventArgs e)
        {
            GraphicsLayer originalGraphicsLayer = MyMap.Layers["OriginalLineGraphicsLayer"] as GraphicsLayer;
            foreach (Graphic g in e.FeatureSet.Features)
            {
                g.Symbol = LayoutRoot.Resources["DefaultLineSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol;
                g.Geometry.SpatialReference = e.UserState as SpatialReference;
                originalGraphicsLayer.Graphics.Add(g);

                foreach (ESRI.ArcGIS.Client.Geometry.PointCollection pc in (g.Geometry as Polyline).Paths)
                {
                    foreach (MapPoint point in pc)
                    {
                        Graphic vertice = new Graphic()
                        {
                            Symbol = LayoutRoot.Resources["DefaultMarkerSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol,
                            Geometry = point
                        };
                        originalGraphicsLayer.Graphics.Add(vertice);
                    }
                }
            }
            GeneralizeButton.IsEnabled = true;
        }

        private void GeneralizeButton_Click(object sender, RoutedEventArgs e)
        {
            GeneralizeButton.IsEnabled = false;
            SliderStackPanel.Visibility = Visibility.Collapsed;

            GraphicsLayer originalGraphicsLayer = MyMap.Layers["OriginalLineGraphicsLayer"] as GraphicsLayer;

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

            GeneralizeParameters generalizeParameters = new GeneralizeParameters()
            {
                DeviationUnit = LinearUnit.SurveyMile,
                MaxDeviation = 10
            };

            geometryService.GeneralizeAsync(new List<Graphic>() { originalGraphicsLayer.Graphics[0] }, generalizeParameters);
        }

        void GeometryService_GeneralizeCompleted(object sender, GraphicsEventArgs e)
        {
            GraphicsLayer generalizedGraphicsLayer = MyMap.Layers["GeneralizedLineGraphicsLayer"] as GraphicsLayer;
            generalizedGraphicsLayer.ClearGraphics();

            foreach (Graphic g in e.Results)
            {
                g.Symbol = LayoutRoot.Resources["NewLineSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol;
                generalizedGraphicsLayer.Graphics.Add(g);

                ESRI.ArcGIS.Client.Geometry.Polyline p = g.Geometry as ESRI.ArcGIS.Client.Geometry.Polyline;

                foreach (ESRI.ArcGIS.Client.Geometry.PointCollection pc in p.Paths)
                {
                    foreach (MapPoint point in pc)
                    {
                        Graphic vertice = new Graphic()
                        {
                            Symbol = LayoutRoot.Resources["NewMarkerSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol,
                            Geometry = point
                        };
                        generalizedGraphicsLayer.Graphics.Add(vertice);
                    }
                }
            }
            generalizedGraphicsLayer.Opacity = 0.75;
            SliderStackPanel.Visibility = Visibility.Visible;
            GeneralizeButton.IsEnabled = true;
        }

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

        private void GeneralizeLayerOpacity_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
        {
            if (MyMap != null)
                MyMap.Layers["GeneralizedLineGraphicsLayer"].Opacity = e.NewValue;
        }
    }
}

VB.NET

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

Namespace ArcGISWPFSDK
    Partial Public Class Generalize
        Inherits UserControl
        Private originalGraphicsLayer As GraphicsLayer

        Public Sub New()
            InitializeComponent()
            AddHandler MyMap.Layers.LayersInitialized, AddressOf Layers_LayersInitialized

            originalGraphicsLayer = TryCast(MyMap.Layers("OriginalLineGraphicsLayer"), GraphicsLayer)
        End Sub

        Private Sub Layers_LayersInitialized(sender As Object, args As EventArgs)
            If originalGraphicsLayer IsNot Nothing AndAlso originalGraphicsLayer.Graphics.Count = 0 Then
                Dim queryTask As New QueryTask("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StatesCitiesRivers_USA/MapServer/1")
                Dim query As New Query()
                query.ReturnGeometry = True
                query.OutSpatialReference = MyMap.SpatialReference
                query.Where = "NAME = 'Mississippi'"

                AddHandler queryTask.ExecuteCompleted, AddressOf queryTask_ExecuteCompleted
                AddHandler queryTask.Failed, AddressOf queryTask_Failed
                queryTask.ExecuteAsync(query, query.OutSpatialReference)
            End If
        End Sub

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

        Private Sub queryTask_ExecuteCompleted(sender As Object, e As QueryEventArgs)
            Dim originalGraphicsLayer As GraphicsLayer = TryCast(MyMap.Layers("OriginalLineGraphicsLayer"), GraphicsLayer)
            For Each g As Graphic In e.FeatureSet.Features
                g.Symbol = TryCast(LayoutRoot.Resources("DefaultLineSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol)
                g.Geometry.SpatialReference = TryCast(e.UserState, SpatialReference)
                originalGraphicsLayer.Graphics.Add(g)

                For Each pc As ESRI.ArcGIS.Client.Geometry.PointCollection In TryCast(g.Geometry, Polyline).Paths
                    For Each point As MapPoint In pc
                        Dim vertice As New Graphic() With { _
                         .Symbol = TryCast(LayoutRoot.Resources("DefaultMarkerSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol), _
                         .Geometry = point _
                        }
                        originalGraphicsLayer.Graphics.Add(vertice)
                    Next
                Next
            Next
            GeneralizeButton.IsEnabled = True
        End Sub

        Private Sub GeneralizeButton_Click(sender As Object, e As RoutedEventArgs)
            GeneralizeButton.IsEnabled = False
            SliderStackPanel.Visibility = Visibility.Collapsed

            Dim originalGraphicsLayer As GraphicsLayer = TryCast(MyMap.Layers("OriginalLineGraphicsLayer"), GraphicsLayer)

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

            Dim generalizeParameters As New GeneralizeParameters() With { _
             .DeviationUnit = LinearUnit.SurveyMile, _
             .MaxDeviation = 10 _
            }

            geometryService.GeneralizeAsync(New List(Of Graphic)() From { _
             originalGraphicsLayer.Graphics(0) _
            }, generalizeParameters)
        End Sub

        Private Sub GeometryService_GeneralizeCompleted(sender As Object, e As GraphicsEventArgs)
            Dim generalizedGraphicsLayer As GraphicsLayer = TryCast(MyMap.Layers("GeneralizedLineGraphicsLayer"), GraphicsLayer)
            generalizedGraphicsLayer.ClearGraphics()

            For Each g As Graphic In e.Results
                g.Symbol = TryCast(LayoutRoot.Resources("NewLineSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol)
                generalizedGraphicsLayer.Graphics.Add(g)

                Dim p As ESRI.ArcGIS.Client.Geometry.Polyline = TryCast(g.Geometry, ESRI.ArcGIS.Client.Geometry.Polyline)

                For Each pc As ESRI.ArcGIS.Client.Geometry.PointCollection In p.Paths
                    For Each point As MapPoint In pc
                        Dim vertice As New Graphic() With { _
                         .Symbol = TryCast(LayoutRoot.Resources("NewMarkerSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol), _
                         .Geometry = point _
                        }
                        generalizedGraphicsLayer.Graphics.Add(vertice)
                    Next
                Next
            Next
            generalizedGraphicsLayer.Opacity = 0.75
            SliderStackPanel.Visibility = Visibility.Visible
            GeneralizeButton.IsEnabled = True
        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 GeneralizeLayerOpacity_ValueChanged(sender As Object, e As RoutedPropertyChangedEventArgs(Of Double))
            If MyMap IsNot Nothing Then
                MyMap.Layers("GeneralizedLineGraphicsLayer").Opacity = e.NewValue
            End If
        End Sub
    End Class
End Namespace