topic Re: Populating DataGrid from quering online image services in .NET Maps SDK Questions

Populating DataGrid from quering online image services

ManishShrivastav — Thu, 11 Mar 2021 05:39:59 GMT

Hi,

I am trying to develop a WPF app that can populate a datagrid by querying an online image service. http://sampleserver6.arcgisonline.com/arcgis/rest/services/USA/MapServer Particularly, I want to search for a name from the sublayers (search for a city, county, or state) and populate the result in a datagrid. I am attaching an image of the result that I want to have and an image of error message that I got. Also I am attaching the code file.

please help

using Esri.ArcGISRuntime.Mapping; using Esri.ArcGISRuntime.Data; using Esri.ArcGISRuntime.Geometry; using Esri.ArcGISRuntime.Tasks; using Esri.ArcGISRuntime.UI; using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows; using System.Windows.Controls; using System.Windows.Data; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Imaging; using System.Windows.Navigation; using System.Windows.Shapes; namespace MapApp { /// <summary> /// Interaction logic for MainWindow.xaml /// </summary> public partial class MainWindow : Window { public MainWindow() { InitializeComponent(); Map myMap = new Map(Basemap.CreateImagery()); ArcGISMapImageLayer layer = new ArcGISMapImageLayer(new Uri("http://sampleserver6.arcgisonline.com/arcgis/rest/services/USA/MapServer")); myMap.OperationalLayers.Add(layer); MyMapView.Map = myMap; } private async void Button_Click(object sender, RoutedEventArgs e) { ArcGISMapImageLayer usaMapImageLayer = (ArcGISMapImageLayer)MyMapView.Map.OperationalLayers[0]; try { // Use a utility method on the map image layer to load all the sublayers and tables. await usaMapImageLayer.LoadTablesAndLayersAsync(); // Get the sublayers of interest. ArcGISMapImageSublayer citiesSublayer = (ArcGISMapImageSublayer)usaMapImageLayer.Sublayers[0]; ArcGISMapImageSublayer countiesSublayer = (ArcGISMapImageSublayer)usaMapImageLayer.Sublayers[3]; ArcGISMapImageSublayer statesSublayer = (ArcGISMapImageSublayer)usaMapImageLayer.Sublayers[2]; // Get the service feature table for each of the sublayers. ServiceFeatureTable citiesTable = citiesSublayer.Table; ServiceFeatureTable countiesTable = countiesSublayer.Table; ServiceFeatureTable statesTable = statesSublayer.Table; // Create the query parameters that will find features. QueryParameters citiesNameQuery = new QueryParameters { WhereClause = "AREANAME=" + SearchTextBox.Text, Geometry = MyMapView.GetCurrentViewpoint(ViewpointType.BoundingGeometry).TargetGeometry, OutSpatialReference = MyMapView.SpatialReference }; QueryParameters countiesNameQuery = new QueryParameters { WhereClause = "NAME=" + SearchTextBox.Text, Geometry = MyMapView.GetCurrentViewpoint(ViewpointType.BoundingGeometry).TargetGeometry, OutSpatialReference = MyMapView.SpatialReference }; QueryParameters statesNameQuery = new QueryParameters { WhereClause = "STATE_NAME=" + SearchTextBox.Text, Geometry = MyMapView.GetCurrentViewpoint(ViewpointType.BoundingGeometry).TargetGeometry, OutSpatialReference = MyMapView.SpatialReference }; // Query each of the sublayers with the query parameters. FeatureQueryResult citiesQueryResult = await citiesTable.QueryFeaturesAsync(citiesNameQuery); FeatureQueryResult countiesQueryResult = await citiesTable.QueryFeaturesAsync(countiesNameQuery); FeatureQueryResult statesQueryResult = await citiesTable.QueryFeaturesAsync(statesNameQuery); var foundCities = 0; var foundCounties = 0; var foundStates = 0; // Loop through results, count the matches found in each layer. foreach (Feature city in citiesQueryResult) { foundCities++; } foreach (Feature county in countiesQueryResult) { foundCounties++; } foreach (Feature states in statesQueryResult) { foundStates++; } // Report the number of matches for each layer. var msg = $"Found {foundCities} cities, {foundCounties} counties, and {foundStates} states containing {SearchTextBox.Text}" + $"in a Name attribute."; MessageBox.Show(msg); // Bind the results to a DataGrid Control on the page MyDataGrid.ItemsSource = citiesQueryResult; } catch (Exception ex) { MessageBox.Show(ex.ToString(), "Error"); } } } }

Thanks

Re: Populating DataGrid from quering online image services

MaximilianGlas — Thu, 11 Mar 2021 08:35:55 GMT

You have 2 issues in your code. That's the correct way.

WhereClauses are missing a quote:

QueryParameters citiesNameQuery = new QueryParameters { WhereClause = $"AREANAME='{SearchTextBox.Text}'", Geometry = MyMapView.GetCurrentViewpoint(ViewpointType.BoundingGeometry).TargetGeometry, OutSpatialReference = MyMapView.SpatialReference }; QueryParameters countiesNameQuery = new QueryParameters { WhereClause = $"NAME='{SearchTextBox.Text}'", Geometry = MyMapView.GetCurrentViewpoint(ViewpointType.BoundingGeometry).TargetGeometry, OutSpatialReference = MyMapView.SpatialReference }; QueryParameters statesNameQuery = new QueryParameters { WhereClause = $"STATE_NAME='{SearchTextBox.Text}'", Geometry = MyMapView.GetCurrentViewpoint(ViewpointType.BoundingGeometry).TargetGeometry, OutSpatialReference = MyMapView.SpatialReference };

And you referenced the same table three times, you need to use the associated tables:

FeatureQueryResult citiesQueryResult = await citiesTable.QueryFeaturesAsync(citiesNameQuery); FeatureQueryResult countiesQueryResult = await countiesTable.QueryFeaturesAsync(countiesNameQuery); FeatureQueryResult statesQueryResult = await statesTable.QueryFeaturesAsync(statesNameQuery);

Then it will work.

Re: Populating DataGrid from quering online image services

ManishShrivastav — Thu, 11 Mar 2021 18:07:35 GMT

Thanks MaximilianGlas. This worked well for me. But still I am not able show the results in the data grid. I tried to bind the query results to the datagrid using the following code.

Code Snippet

// Query each of the sublayers with the query parameters. FeatureQueryResult citiesQueryResult = await citiesTable.QueryFeaturesAsync(citiesNameQuery); FeatureQueryResult countiesQueryResult = await countiesTable.QueryFeaturesAsync(countiesNameQuery); FeatureQueryResult statesQueryResult = await statesTable.QueryFeaturesAsync(statesNameQuery); var foundCities = 0; var foundCounties = 0; var foundStates = 0; // Loop through results, count the matches found in each layer. foreach (Feature city in citiesQueryResult) { foundCities++; } foreach (Feature county in countiesQueryResult) { foundCounties++; } foreach (Feature states in statesQueryResult) { foundStates++; } // Report the number of matches for each layer. var msg = $"Found {foundCities} cities, {foundCounties} counties, and {foundStates} states containing {SearchTextBox.Text}" + $" in a Name attribute."; MessageBox.Show(msg); // Bind the results to a DataGrid Control on the page MyDataGrid.ItemsSource = citiesQueryResult; MyDataGrid.ItemsSource = countiesQueryResult; MyDataGrid.ItemsSource = statesQueryResult; }