Attribute Query

This sample demonstrates using the ArcGIS Runtime SDK for WPF to perform an attribute query on local data, add the results to the map and a DataGrid, and zoom to the result. To use the sample, select a state from the drop-down menu in the upper right corner of the application.

In the sample's code-behind, a QueryTask is used to query a states local map service based on the name selected in the drop-down menu. The result is then added as a Graphic to the map and displayed in the DataGrid.

XAML

<UserControl x:Class="ArcGISWPFSDK.LocalAttributeQuery"
             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>
            <BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter"/>
            <esri:SimpleFillSymbol x:Key="DefaultFillSymbol" Fill="#500000FF" BorderBrush="Blue" BorderThickness="1" />
            <esri:PictureMarkerSymbol x:Key="DefaultPictureSymbol" OffsetX="35" OffsetY="35" 
                 Source="\Assets\Images\i_about.png" />
            <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" WrapAround="True" Extent="-15000000,2000000,-7000000,8000000" Background="#FFE3E3E3" MinimumResolution="2445.98490512499" >
            <esri:Map.Layers>
                <esri:ArcGISLocalTiledLayer ID="BaseMap" Path="..\\Data\\TPKs\\Topographic.tpk"/>
                <esri:ArcGISLocalDynamicMapServiceLayer Path="..\\Data\\MPKS\\USCitiesStates.mpk"/>
                <esri:GraphicsLayer ID="MyGraphicsLayer" />
            </esri:Map.Layers>
        </esri:Map>
        <StackPanel Orientation="Vertical" Margin="10" HorizontalAlignment="Right" VerticalAlignment="Top" >
            <Grid x:Name="QueryGrid" HorizontalAlignment="Right" VerticalAlignment="Top" Margin="0,7,7,0" >
                <Rectangle Fill="{StaticResource PanelGradient}" Stroke="Gray"  RadiusX="10" RadiusY="10" Margin="0,0,0,5">
                    <Rectangle.Effect>
                        <DropShadowEffect/>
                    </Rectangle.Effect>
                </Rectangle>
                <TextBlock x:Name="DataDisplayTitleBottom" Text="Query a layer" Foreground="White" FontSize="12" 
                      Margin="10,3,0,5" />
                <StackPanel Orientation="Vertical" Margin="15" HorizontalAlignment="Center" VerticalAlignment="Top" >
                    <ComboBox x:Name="QueryComboBox" MinWidth="150" SelectionChanged="QueryComboBox_SelectionChanged"
                         Margin="5,10,5,5" >
                    </ComboBox>
                    <ScrollViewer x:Name="DataGridScrollViewer" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Auto"  
                         Width="230" MaxHeight="340" Visibility="Collapsed">
                        <DataGrid x:Name="QueryDetailsDataGrid" AutoGenerateColumns="False" HeadersVisibility="None" 
                              Background="White">
                            <DataGrid.Columns>
                                <DataGridTextColumn Width="95" Binding="{Binding Path=Key}" FontWeight="Bold" IsReadOnly="True"/>
                                <DataGridTextColumn Width="115" Binding="{Binding Path=Value}" IsReadOnly="True"/>
                            </DataGrid.Columns>
                        </DataGrid>
                    </ScrollViewer>
                </StackPanel>
            </Grid>
        </StackPanel>
        <ProgressBar x:Name="MyProgressBar" IsIndeterminate="True" VerticalAlignment="Bottom" Width="200" Height="20" Margin="10" Visibility="{Binding Path=IsBusy, Converter={StaticResource BooleanToVisibilityConverter}}"></ProgressBar>
    </Grid>
</UserControl>

C#

using System;
using System.Windows;
using System.Windows.Controls;
using ESRI.ArcGIS.Client.Tasks;
using ESRI.ArcGIS.Client.Local;
using ESRI.ArcGIS.Client;
using System.ComponentModel;

namespace ArcGISWPFSDK
{

    public partial class LocalAttributeQuery : UserControl, INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        private bool _isBusy = true;

        public bool IsBusy
        {
            get
            {
                return _isBusy;
            }
            set
            {
                _isBusy = value;

                if (PropertyChanged != null)
                {

                    PropertyChanged(this, new PropertyChangedEventArgs("IsBusy"));
                }
            }
        }    
        LocalMapService _mapService;

        public LocalAttributeQuery()
        {
            InitializeComponent();

            QueryComboBox.IsEnabled = false;

            LocalMapService.GetServiceAsync("..\\Data\\MPKS\\USCitiesStates.mpk", (localMapService) =>
            {
                _mapService = localMapService;
                QueryComboBox.IsEnabled = true;
                QueryTask queryTask = new QueryTask();
                queryTask.Url = _mapService.UrlMapService + "/2";
                queryTask.ExecuteCompleted += QueryTask_ExecuteCompleted;
                queryTask.Failed += QueryTask_Failed;
                ESRI.ArcGIS.Client.Tasks.Query query = new ESRI.ArcGIS.Client.Tasks.Query();
                query.ReturnGeometry = false;
                query.Where = "1=1";
                queryTask.ExecuteAsync(query, "initial");
                DataContext = this;
                IsBusy = false;
            });
        }

        private void QueryComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            if (QueryComboBox.SelectedItem.ToString().Contains("Select..."))
                return;
            QueryTask queryTask2 = new QueryTask(_mapService.UrlMapService + "/2");
            queryTask2.ExecuteCompleted += QueryTask_ExecuteCompleted;
            queryTask2.Failed += QueryTask_Failed;
            ESRI.ArcGIS.Client.Tasks.Query query2 = new ESRI.ArcGIS.Client.Tasks.Query();
            query2.OutFields.Add("*");
            query2.Where = "STATE_NAME = '" + QueryComboBox.SelectedItem.ToString() + "'";
            query2.ReturnGeometry = true;
            queryTask2.ExecuteAsync(query2);
        }

        private void QueryTask_ExecuteCompleted(object sender, ESRI.ArcGIS.Client.Tasks.QueryEventArgs args)
        {
            FeatureSet featureSet = args.FeatureSet;

            // If initial query to populate states combobox
            if ((args.UserState as string) == "initial")
            {
                // Just show on initial load
                QueryComboBox.Items.Add("Select...");

                foreach (Graphic graphic in args.FeatureSet.Features)
                {
                    QueryComboBox.Items.Add(graphic.Attributes["STATE_NAME"].ToString());
                }

                QueryComboBox.SelectedIndex = 0;
                return;
            }

            // Remove the first entry if "Select..."
            if (QueryComboBox.Items[0].ToString().Contains("Select..."))
                QueryComboBox.Items.RemoveAt(0);

            // If an item has been selected            
            GraphicsLayer graphicsLayer = MyMap.Layers["MyGraphicsLayer"] as GraphicsLayer;
            graphicsLayer.ClearGraphics();

            if (featureSet != null && featureSet.Features.Count > 0)
            {
                // Show selected feature attributes in DataGrid
                Graphic selectedFeature = featureSet.Features[0];

                QueryDetailsDataGrid.ItemsSource = selectedFeature.Attributes;

                // Hightlight selected feature
                selectedFeature.Symbol = LayoutRoot.Resources["DefaultFillSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol;
                graphicsLayer.Graphics.Add(selectedFeature);

                // Zoom to selected feature (define expand percentage)
                ESRI.ArcGIS.Client.Geometry.Envelope selectedFeatureExtent = selectedFeature.Geometry.Extent;

                double expandPercentage = 30;

                double widthExpand = selectedFeatureExtent.Width * (expandPercentage / 100);
                double heightExpand = selectedFeatureExtent.Height * (expandPercentage / 100);

                ESRI.ArcGIS.Client.Geometry.Envelope displayExtent = new ESRI.ArcGIS.Client.Geometry.Envelope(
                selectedFeatureExtent.XMin - (widthExpand / 2),
                selectedFeatureExtent.YMin - (heightExpand / 2),
                selectedFeatureExtent.XMax + (widthExpand / 2),
                selectedFeatureExtent.YMax + (heightExpand / 2));

                MyMap.ZoomTo(displayExtent);

                if (DataGridScrollViewer.Visibility == Visibility.Collapsed)
                {
                    DataGridScrollViewer.Visibility = Visibility.Visible;
                    QueryGrid.Height = Double.NaN;
                    QueryGrid.UpdateLayout();
                }
            }
            else
            {
                QueryDetailsDataGrid.ItemsSource = null;
                DataGridScrollViewer.Visibility = Visibility.Collapsed;
                QueryGrid.Height = Double.NaN;
                QueryGrid.UpdateLayout();
            }
        }

        private void QueryTask_Failed(object sender, TaskFailedEventArgs args)
        {
            MessageBox.Show("Query failed: " + args.Error);
        }
    }
}

VB.NET

Imports System.Windows
Imports System.Windows.Controls
Imports ESRI.ArcGIS.Client.Tasks
Imports ESRI.ArcGIS.Client.Local
Imports ESRI.ArcGIS.Client
Imports ESRI.ArcGIS.Client.Geometry
Imports System.ComponentModel

Namespace ArcGISWPFSDK
    Partial Public Class LocalAttributeQuery
        Inherits UserControl
        Implements INotifyPropertyChanged
        Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged
        Private _isBusy As Boolean = True
        Public Property IsBusy() As Boolean
            Get
                Return _isBusy
            End Get
            Set(value As Boolean)
                _isBusy = value

                RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs("IsBusy"))
            End Set
        End Property
        Private _mapService As LocalMapService

        Public Sub New()
            InitializeComponent()

            QueryComboBox.IsEnabled = False

            LocalMapService.GetServiceAsync("..\Data\MPKS\USCitiesStates.mpk", Function(localMapService__1)
                                                                                   _mapService = localMapService__1
                                                                                   QueryComboBox.IsEnabled = True
                                                                                   Dim queryTask As New QueryTask()
                                                                                   queryTask.Url = _mapService.UrlMapService & "/2"
                                                                                   AddHandler queryTask.ExecuteCompleted, AddressOf QueryTask_ExecuteCompleted
                                                                                   AddHandler queryTask.Failed, AddressOf QueryTask_Failed
                                                                                   Dim query As New ESRI.ArcGIS.Client.Tasks.Query()
                                                                                   query.ReturnGeometry = False
                                                                                   query.Where = "1=1"
                                                                                   queryTask.ExecuteAsync(query, "initial")
                                                                                   DataContext = Me
                                                                                   IsBusy = False
                                                                               End Function)
        End Sub

        Private Sub QueryComboBox_SelectionChanged(sender As Object, e As SelectionChangedEventArgs)
            If QueryComboBox.SelectedItem.ToString().Contains("Select...") Then
                Return
            End If
            Dim queryTask2 As New QueryTask(_mapService.UrlMapService & "/2")
            AddHandler queryTask2.ExecuteCompleted, AddressOf QueryTask_ExecuteCompleted
            AddHandler queryTask2.Failed, AddressOf QueryTask_Failed
            Dim query2 As New ESRI.ArcGIS.Client.Tasks.Query()
            query2.OutFields.Add("*")
            query2.Where = "STATE_NAME = '" & QueryComboBox.SelectedItem.ToString() & "'"
            query2.ReturnGeometry = True
            queryTask2.ExecuteAsync(query2)
        End Sub

        Private Sub QueryTask_ExecuteCompleted(sender As Object, args As ESRI.ArcGIS.Client.Tasks.QueryEventArgs)
            Dim featureSet As FeatureSet = args.FeatureSet

            ' If initial query to populate states combobox
            If TryCast(args.UserState, String) = "initial" Then
                ' Just show on initial load
                QueryComboBox.Items.Add("Select...")

                For Each graphic As Graphic In args.FeatureSet.Features
                    QueryComboBox.Items.Add(graphic.Attributes("STATE_NAME").ToString())
                Next

                QueryComboBox.SelectedIndex = 0
                Return
            End If

            ' Remove the first entry if "Select..."
            If QueryComboBox.Items(0).ToString().Contains("Select...") Then
                QueryComboBox.Items.RemoveAt(0)
            End If

            ' If an item has been selected            
            Dim graphicsLayer As GraphicsLayer = TryCast(MyMap.Layers("MyGraphicsLayer"), GraphicsLayer)
            graphicsLayer.ClearGraphics()

            If featureSet IsNot Nothing AndAlso featureSet.Features.Count > 0 Then
                ' Show selected feature attributes in DataGrid
                Dim selectedFeature As Graphic = featureSet.Features(0)

                QueryDetailsDataGrid.ItemsSource = selectedFeature.Attributes

                ' Hightlight selected feature
                selectedFeature.Symbol = TryCast(LayoutRoot.Resources("DefaultFillSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol)
                graphicsLayer.Graphics.Add(selectedFeature)

                ' Zoom to selected feature (define expand percentage)
                Dim selectedFeatureExtent As ESRI.ArcGIS.Client.Geometry.Envelope = selectedFeature.Geometry.Extent

                Dim expandPercentage As Double = 30

                Dim widthExpand As Double = selectedFeatureExtent.Width * (expandPercentage / 100)
                Dim heightExpand As Double = selectedFeatureExtent.Height * (expandPercentage / 100)

                Dim displayExtent As New ESRI.ArcGIS.Client.Geometry.Envelope(selectedFeatureExtent.XMin - (widthExpand / 2), selectedFeatureExtent.YMin - (heightExpand / 2), selectedFeatureExtent.XMax + (widthExpand / 2), selectedFeatureExtent.YMax + (heightExpand / 2))

                MyMap.ZoomTo(displayExtent)

                If DataGridScrollViewer.Visibility = Visibility.Collapsed Then
                    DataGridScrollViewer.Visibility = Visibility.Visible
                    QueryGrid.Height = [Double].NaN
                    QueryGrid.UpdateLayout()
                End If
            Else
                QueryDetailsDataGrid.ItemsSource = Nothing
                DataGridScrollViewer.Visibility = Visibility.Collapsed
                QueryGrid.Height = [Double].NaN
                QueryGrid.UpdateLayout()
            End If
        End Sub

        Private Sub QueryTask_Failed(sender As Object, args As TaskFailedEventArgs)
            MessageBox.Show("Query failed: " & Convert.ToString(args.[Error]))
        End Sub
    End Class
End Namespace