前台
<UserControl x:Class="ArcGISSilverlightSDK.AttributeQuery" 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" xmlns:slData="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data"> <Grid x:Name="LayoutRoot" Background="White">
<Grid.Resources> <esri:SimpleFillSymbol x:Key="DefaultFillSymbol" Fill="#500000FF" BorderBrush="Blue" BorderThickness="1" /> </Grid.Resources>
<esri:Map x:Name="MyMap" WrapAround="True" Extent="-15000000,2000000,-7000000,8000000"> <esri:ArcGISTiledMapServiceLayer ID="StreetMapLayer" Url="http://services.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer"/> <esri:GraphicsLayer ID="MyGraphicsLayer" /> </esri:Map>
<Border x:Name="QueryBorder" Background="#77919191" BorderThickness="1" CornerRadius="5" HorizontalAlignment="Right" BorderBrush="Gray" VerticalAlignment="Top" Margin="5"> <Border.Effect> <DropShadowEffect/> </Border.Effect> <Grid x:Name="QueryGrid" HorizontalAlignment="Right" VerticalAlignment="Top" > <Grid.RowDefinitions> <RowDefinition Height="30" /> <RowDefinition Height="30" /> <RowDefinition Height="*" /> </Grid.RowDefinitions> <TextBlock x:Name="DataDisplayTitleBottom" Text="Query a layer (search for a state)" Foreground="White" FontSize="10" Grid.Row="0" Margin="15,5,15,1" HorizontalAlignment="Center" > <TextBlock.Effect> <DropShadowEffect /> </TextBlock.Effect> </TextBlock> <ComboBox x:Name="QueryComboBox" Grid.Row="1" MinWidth="150" SelectionChanged="QueryComboBox_SelectionChanged" Margin="5,1,5,5" > </ComboBox> <ScrollViewer x:Name="DataGridScrollViewer" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Auto" Width="230" MinHeight="200" Visibility="Collapsed" Grid.Row="2"> <slData:DataGrid x:Name="QueryDetailsDataGrid" AutoGenerateColumns="False" HeadersVisibility="None" Background="White"> <slData:DataGrid.Columns> <slData:DataGridTextColumn Binding="{Binding Path=Key}" FontWeight="Bold"/> <slData:DataGridTextColumn Binding="{Binding Path=Value}"/> </slData:DataGrid.Columns> </slData:DataGrid> </ScrollViewer> </Grid> </Border>
</Grid> </UserControl>
后台
using System; using System.Windows; using System.Windows.Controls; using ESRI.ArcGIS.Client; using ESRI.ArcGIS.Client.Tasks;
namespace ArcGISSilverlightSDK { public partial class AttributeQuery : UserControl { public AttributeQuery() { InitializeComponent();
QueryTask queryTask = new QueryTask("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Demographics/ESRI_Census_USA/MapServer/5"); queryTask.ExecuteCompleted += QueryTask_ExecuteCompleted; queryTask.Failed += QueryTask_Failed;
ESRI.ArcGIS.Client.Tasks.Query query = new ESRI.ArcGIS.Client.Tasks.Query();
// Specify fields to return from initial query query.OutFields.AddRange(new string[] { "STATE_NAME" });
// This query will just populate the drop-down, so no need to return geometry query.ReturnGeometry = false;
// Return all features query.Where = "1=1"; queryTask.ExecuteAsync(query, "initial"); }
private void QueryComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e) { if (QueryComboBox.SelectedItem.ToString().Contains("Select...")) return;
QueryTask queryTask = new QueryTask("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Demographics/ESRI_Census_USA/MapServer/5"); queryTask.ExecuteCompleted += QueryTask_ExecuteCompleted; queryTask.Failed += QueryTask_Failed; ESRI.ArcGIS.Client.Tasks.Query query = new ESRI.ArcGIS.Client.Tasks.Query(); query.ReturnGeometry = true; query.Text = QueryComboBox.SelectedItem.ToString(); query.OutSpatialReference = MyMap.SpatialReference; query.OutFields.Add("*");
queryTask.ExecuteAsync(query); }
private void QueryTask_ExecuteCompleted(object sender, ESRI.ArcGIS.Client.Tasks.QueryEventArgs args) { FeatureSet featureSet = args.FeatureSet;
// If initial query to populate states combo box 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.Graphics.Clear();
if (featureSet != null && featureSet.Features.Count > 0) { // Show selected feature attributes in DataGrid Graphic selectedFeature = featureSet.Features[0];
QueryDetailsDataGrid.ItemsSource = selectedFeature.Attributes;
// Highlight 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 DataGrid not visible (initial load), show it 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); } } }