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Query data using a time extent.
Use case
This workflow can be used to return records that are between a specified start and end date. For example, records of Canada goose sightings over time could be queried to only show sightings during the winter migration time period.
How to use the sample
Run the sample, and a subset of records will be displayed on the map.
How it works
An instance of ServiceFeatureTable is created by passing a URL to the REST endpoint of a time-enabled service. Time-enabled services will have TimeInfo defined in the service description. This information is specified in ArcMap or ArcGIS Pro prior to publishing the service.
The feature request mode of the ServiceFeatureTable is set to ManualCache, so that the developer can control how and when the feature table is populated with data.
A FeatureLayer is created by passing in the instance of the ServiceFeatureTable.
A TimeExtent object is created by specifying start and end date/time objects.
A QueryParmaters object is created with the TimeExtent.
ServiceFeatureTable.PopulateFromService is executed by passing in the QueryParameters.
The feature table is populated with data that matches the provided query.
Relevant API
QueryParameters
ServiceFeatureTable.PopulateFromService
TimeExtent
About the data
This sample uses Atlantic hurricane data from the year 2000. The data is from the National Hurricane Center (NOAA / National Weather Service).
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// Copyright 2017 Esri.//// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.// You may obtain a copy of the License at: http://www.apache.org/licenses/LICENSE-2.0//// Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific// language governing permissions and limitations under the License.using Esri.ArcGISRuntime;
using Esri.ArcGISRuntime.Data;
using Esri.ArcGISRuntime.Mapping;
using System;
using System.Windows;
namespaceArcGIS.WPF.Samples.TimeBasedQuery{
[ArcGIS.Samples.Shared.Attributes.Sample(
name: "Time-based query",
category: "Layers",
description: "Query data using a time extent.",
instructions: "Run the sample, and a subset of records will be displayed on the map.",
tags: new[] { "query", "time", "time extent" })]
publicpartialclassTimeBasedQuery {
// Hold a URI pointing to the feature serviceprivate Uri _serviceUri = new Uri("https://sampleserver6.arcgisonline.com/arcgis/rest/services/Hurricanes/MapServer/0");
// Hold a reference to the feature table used by the sampleprivate ServiceFeatureTable _myFeatureTable;
publicTimeBasedQuery() {
InitializeComponent();
// Create the UI, setup the control references and execute initialization Initialize();
}
privatevoidInitialize() {
// Create a new map with oceans basemap Map myMap = new Map(BasemapStyle.ArcGISOceans);
// Create feature table for the hurricane feature service _myFeatureTable = new ServiceFeatureTable(_serviceUri)
{
// Define the request mode FeatureRequestMode = FeatureRequestMode.ManualCache
};
// When feature table is loaded, populate data _myFeatureTable.LoadStatusChanged += OnLoadedPopulateData;
// Create FeatureLayer that uses the created table FeatureLayer myFeatureLayer = new FeatureLayer(_myFeatureTable);
// Add created layer to the map myMap.OperationalLayers.Add(myFeatureLayer);
// Assign the Map to the MapView MyMapView.Map = myMap;
}
privateasyncvoidOnLoadedPopulateData(object sender, LoadStatusEventArgs e) {
// If layer isn't loaded, do nothingif (e.Status != LoadStatus.Loaded) { return; }
// Create new query object that contains a basic 'include everything' clause QueryParameters queryParameters = new QueryParameters()
{
WhereClause = "1=1" };
// Create a new time extent that covers the desired interval (beginning of time to September 16th, 2000) TimeExtent myExtent = new TimeExtent(new DateTime(1, 1, 1), new DateTime(2000, 9, 16));
// Apply the time extent to the query parameters queryParameters.TimeExtent = myExtent;
// Create list of the fields that are returned from the servicestring[] outputFields = { "*" };
try {
// Populate feature table with the data based on queryawait _myFeatureTable.PopulateFromServiceAsync(queryParameters, true, outputFields);
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString(), "Error");
}
}
}
}