Clip Features Online

This sample demonstrates use of the Geoprocessor to call a ClipFeatures geoprocessing service. To use the sample, specify a distance, then click subsequent points on the map to draw a line. Double-click to finish the line. When the line is finished, county features within the specified distance of the line will be returned and drawn map, with their boundaries clipped to the buffer area.

In the code-behind, a Geoprocessor is used to pass the distance and line to the ClipFeatures service. When the results are returned, they are checked to see whether they contain any features. If they do not, then the operation generated too many features to be sent back to the client as graphics, and instead generated a result image. In this case, the result image is requested. Once either the graphics or the result image has been retrieved, they are added to the map.

XAML

<UserControl x:Class="ArcGISWPFSDK.ClipFeatures"
    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:SimpleLineSymbol x:Key="ClipLineSymbol" Color="Red" Width="2" />
            <esri:SimpleFillSymbol x:Key="ClipFeaturesFillSymbol" Fill="#770000FF" BorderBrush="#FF0000FF" BorderThickness="1"  />
            <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" Background="White" Extent="-130,10,-70,60">
            <esri:ArcGISTiledMapServiceLayer ID="StreetMapLayer" 
                    Url="http://services.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer"/>
            <esri:GraphicsLayer ID="MyResultGraphicsLayer" >
                <esri:GraphicsLayer.MapTip>
                    <Grid Background="LightYellow">
                        <StackPanel Orientation="Horizontal" Margin="5">
                            <TextBlock Text="County name: " FontWeight="Bold" Foreground="Black"/>
                            <TextBlock Text="{Binding [NAME]}" Foreground="Black"/>
                        </StackPanel>
                        <Border BorderBrush="Black" BorderThickness="1" />
                    </Grid>
                </esri:GraphicsLayer.MapTip>
            </esri:GraphicsLayer>
            <esri:GraphicsLayer ID="MyGraphicsLayer" />
        </esri:Map>

        <Grid HorizontalAlignment="Right" VerticalAlignment="Top" Margin="0,15,15,0" >
            <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="5,5,5,10" />
            <StackPanel Orientation="Vertical" Margin="10,10,10,10" HorizontalAlignment="Left" >
                <TextBlock Text="Clip polygon features - US counties" HorizontalAlignment="Center" FontWeight="Bold" Foreground="Black"
                           Margin="5,5,5,5"/>
                <TextBlock x:Name="InformationTextBlock" Text="Draw a line on the map over the United States. When finished the line will be buffered and the buffer will be used to clip US county polygons. Results are returned as a GP map image."
                    Width="200" TextAlignment="Left" TextWrapping="Wrap" Foreground="Black" />
                <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="5,5,5,10">
                    <TextBlock Text="Distance (in miles): " VerticalAlignment="Center" Foreground="Black" />
                    <TextBox x:Name="DistanceTextBox" Text="100" Width="35" TextAlignment="Right" Margin="0,0,5,0" />
                    <Button x:Name="ClearButton" Content="Clear Results" Click="ClearButton_Click" />
                </StackPanel>
                <TextBlock x:Name="ProcessingTextBlock" MaxWidth="150" Margin="5,5,5,5" Visibility="Collapsed" 
                           HorizontalAlignment="Center" Text="Processing." TextWrapping="Wrap" Foreground="Black" />
            </StackPanel>
        </Grid>

    </Grid>
</UserControl>

C#

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

namespace ArcGISWPFSDK
{
    public partial class ClipFeatures : UserControl
    {
        private DispatcherTimer _processingTimer;
        private Draw MyDrawObject;

        public ClipFeatures()
        {
            InitializeComponent();

            _processingTimer = new System.Windows.Threading.DispatcherTimer();
            _processingTimer.Interval = new TimeSpan(0, 0, 0, 0, 800);
            _processingTimer.Tick += ProcessingTimer_Tick;

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

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

            ProcessingTextBlock.Visibility = Visibility.Visible;
            _processingTimer.Start();

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

            Graphic graphic = new Graphic()
            {
                Symbol = LayoutRoot.Resources["ClipLineSymbol"] as ESRI.ArcGIS.Client.Symbols.LineSymbol,
                Geometry = args.Geometry
            };
            graphicsLayer.Graphics.Add(graphic);

            Geoprocessor geoprocessorTask = new Geoprocessor("http://serverapps.esri.com/ArcGIS/rest/services/" +
                "SamplesNET/USA_Data_ClipTools/GPServer/ClipCounties");
            geoprocessorTask.UpdateDelay = 5000;
            geoprocessorTask.JobCompleted += GeoprocessorTask_JobCompleted;

            List<GPParameter> parameters = new List<GPParameter>();
            parameters.Add(new GPFeatureRecordSetLayer("Input_Features", args.Geometry));
            parameters.Add(new GPLinearUnit("Linear_unit", esriUnits.esriMiles, Int32.Parse(DistanceTextBox.Text)));

            geoprocessorTask.SubmitJobAsync(parameters);
        }

        private void GeoprocessorTask_JobCompleted(object sender, JobInfoEventArgs e)
        {
            Geoprocessor geoprocessorTask = sender as Geoprocessor;

            geoprocessorTask.GetResultDataCompleted += (s1, ev1) =>
            {
                GraphicsLayer graphicsLayer = MyMap.Layers["MyResultGraphicsLayer"] as GraphicsLayer;

                if (ev1.Parameter is GPFeatureRecordSetLayer)
                {
                    GPFeatureRecordSetLayer gpLayer = ev1.Parameter as GPFeatureRecordSetLayer;
                    if (gpLayer.FeatureSet.Features.Count == 0)
                    {
                        geoprocessorTask.GetResultImageLayerCompleted += (s2, ev2) =>
                        {

                            GPResultImageLayer gpImageLayer = ev2.GPResultImageLayer;
                            gpImageLayer.Opacity = 0.5;
                            MyMap.Layers.Add(gpImageLayer);

                            ProcessingTextBlock.Text = "Greater than 500 features returned.  Results drawn using map service.";
                            _processingTimer.Stop();
                        };

                        geoprocessorTask.GetResultImageLayerAsync(e.JobInfo.JobId, "Clipped_Counties");
                        return;
                    }

                    foreach (Graphic graphic in gpLayer.FeatureSet.Features)
                    {
                        graphic.Symbol = LayoutRoot.Resources["ClipFeaturesFillSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol;
                        graphicsLayer.Graphics.Add(graphic);
                    }
                }

                ProcessingTextBlock.Visibility = Visibility.Collapsed;
                _processingTimer.Stop();
            };

            geoprocessorTask.GetResultDataAsync(e.JobInfo.JobId, "Clipped_Counties");
        }

        private void GeoprocessorTask_Failed(object sender, TaskFailedEventArgs e)
        {
            MessageBox.Show("Geoprocessor service failed: " + e.Error);
        }

        private void ClearButton_Click(object sender, RoutedEventArgs e)
        {
            List<Layer> gpResultImageLayers = new List<Layer>();

            foreach (Layer layer in MyMap.Layers)
                if (layer is GraphicsLayer)
                    (layer as GraphicsLayer).ClearGraphics();
                else if (layer is GPResultImageLayer)
                    gpResultImageLayers.Add(layer);
            for (int i = 0; i < gpResultImageLayers.Count; i++)
                MyMap.Layers.Remove(gpResultImageLayers[i]);

            MyDrawObject.IsEnabled = true;

            ProcessingTextBlock.Text = "";
            ProcessingTextBlock.Visibility = Visibility.Collapsed;
        }

        void ProcessingTimer_Tick(object sender, EventArgs e)
        {
            if (ProcessingTextBlock.Text.Length > 20 || !ProcessingTextBlock.Text.StartsWith("Processing"))
                ProcessingTextBlock.Text = "Processing.";
            else
                ProcessingTextBlock.Text = ProcessingTextBlock.Text + ".";
        }
    }
}

VB.NET

Imports System.Collections.Generic
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Threading
Imports ESRI.ArcGIS.Client
Imports ESRI.ArcGIS.Client.Tasks
Namespace ArcGISWPFSDK
    Partial Public Class ClipFeatures
        Inherits UserControl
        Private _processingTimer As DispatcherTimer
        Private MyDrawObject As Draw

        Public Sub New()
            InitializeComponent()

            _processingTimer = New System.Windows.Threading.DispatcherTimer()
            _processingTimer.Interval = New TimeSpan(0, 0, 0, 0, 800)
            AddHandler _processingTimer.Tick, AddressOf ProcessingTimer_Tick

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

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

            ProcessingTextBlock.Visibility = Visibility.Visible
            _processingTimer.Start()

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

            Dim graphic As New Graphic() With { _
             .Symbol = TryCast(LayoutRoot.Resources("ClipLineSymbol"), ESRI.ArcGIS.Client.Symbols.LineSymbol), _
             .Geometry = args.Geometry _
            }
            graphicsLayer.Graphics.Add(graphic)

            Dim geoprocessorTask As New Geoprocessor("http://serverapps.esri.com/ArcGIS/rest/services/" & "SamplesNET/USA_Data_ClipTools/GPServer/ClipCounties")
            geoprocessorTask.UpdateDelay = 5000
            AddHandler geoprocessorTask.JobCompleted, AddressOf GeoprocessorTask_JobCompleted

            Dim parameters As New List(Of GPParameter)()
            parameters.Add(New GPFeatureRecordSetLayer("Input_Features", args.Geometry))
            parameters.Add(New GPLinearUnit("Linear_unit", esriUnits.esriMiles, Int32.Parse(DistanceTextBox.Text)))

            geoprocessorTask.SubmitJobAsync(parameters)
        End Sub

        Private Sub GeoprocessorTask_GetResultDataCompleted(ByVal sender As Object, ByVal e As GPParameterEventArgs)

            Dim geoprocessorTask As Geoprocessor = TryCast(sender, Geoprocessor)
            Dim graphicsLayer As GraphicsLayer = TryCast(MyMap.Layers("MyResultGraphicsLayer"), GraphicsLayer)

            If TypeOf e.Parameter Is GPFeatureRecordSetLayer Then
                Dim gpLayer As GPFeatureRecordSetLayer = TryCast(e.Parameter, GPFeatureRecordSetLayer)

                If gpLayer.FeatureSet.Features.Count = 0 Then
                    AddHandler geoprocessorTask.GetResultImageLayerCompleted, AddressOf GeoprocessorTask_GetResultImageLayerCompleted
                    geoprocessorTask.GetResultImageLayerAsync(TryCast(e.UserState, String), "Clipped_Counties")
                    Return
                End If

                For Each graphic As Graphic In gpLayer.FeatureSet.Features
                    graphic.Symbol = TryCast(LayoutRoot.Resources("ClipFeaturesFillSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol)
                    graphicsLayer.Graphics.Add(graphic)
                Next graphic
            End If

            ProcessingTextBlock.Visibility = Visibility.Collapsed
            _processingTimer.Stop()
        End Sub

        Private Sub GeoprocessorTask_Failed(sender As Object, e As TaskFailedEventArgs)
            MessageBox.Show("Geoprocessor service failed: " & Convert.ToString(e.[Error]))
        End Sub

        Private Sub ClearButton_Click(sender As Object, e As RoutedEventArgs)
            Dim gpResultImageLayers As New List(Of Layer)()

            For Each layer As Layer In MyMap.Layers
                If TypeOf layer Is GraphicsLayer Then
                    TryCast(layer, GraphicsLayer).ClearGraphics()
                ElseIf TypeOf layer Is GPResultImageLayer Then
                    gpResultImageLayers.Add(layer)
                End If
            Next
            For i As Integer = 0 To gpResultImageLayers.Count - 1
                MyMap.Layers.Remove(gpResultImageLayers(i))
            Next

            MyDrawObject.IsEnabled = True

            ProcessingTextBlock.Text = ""
            ProcessingTextBlock.Visibility = Visibility.Collapsed
        End Sub

        Private Sub ProcessingTimer_Tick(sender As Object, e As EventArgs)
            If ProcessingTextBlock.Text.Length > 20 OrElse Not ProcessingTextBlock.Text.StartsWith("Processing") Then
                ProcessingTextBlock.Text = "Processing."
            Else
                ProcessingTextBlock.Text = ProcessingTextBlock.Text & "."
            End If
        End Sub

        Private Sub GeoprocessorTask_GetResultImageLayerCompleted(ByVal s2 As Object, ByVal ev2 As GetResultImageLayerEventArgs)
            Dim gpImageLayer As GPResultImageLayer = ev2.GPResultImageLayer
            gpImageLayer.Opacity = 0.5
            MyMap.Layers.Add(gpImageLayer)
            ProcessingTextBlock.Text = "Greater than 500 features returned.  Results drawn using map service."
            _processingTimer.Stop()
        End Sub

        Private Sub GeoprocessorTask_JobCompleted(ByVal sender As Object, ByVal e As JobInfoEventArgs)
            Dim geoprocessorTask As Geoprocessor = TryCast(sender, Geoprocessor)
            AddHandler geoprocessorTask.GetResultDataCompleted, AddressOf GeoprocessorTask_GetResultDataCompleted

            Dim graphicsLayer As GraphicsLayer = TryCast(MyMap.Layers("MyResultGraphicsLayer"), GraphicsLayer)
            geoprocessorTask.GetResultDataAsync(e.JobInfo.JobId, "Clipped_Counties")
        End Sub

    End Class
End Namespace