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ArcGIS Runtime SDK for .NET

Offline geocode

This code sample is available for these platforms:
View Sample on GitHub

Geocode addresses to locations and reverse geocode locations to addresses offline.

screenshot

How to use the sample

Type the address in the Search menu option or select from the list to Geocode the address and view the result on the map. Tap the location you want to reverse geocode. Tap the pin to see the full address.

How it works

  1. Use the path of a .loc file to create a LocatorTask object.
  2. Set up GeocodeParameters and call GeocodeAsync to get geocode results.

Relevant API

  • GeocodeParameters
  • GeocodeResult
  • LocatorTask
  • ReverseGeocodeParameters

Offline data

This sample downloads the following items from ArcGIS Online automatically:

Tags

Search and Query, geocode, geocoder, locator, offline, package

Sample Code

<UserControl 
    x:Class="ArcGISRuntime.UWP.Samples.OfflineGeocode.OfflineGeocode"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:esriUI="using:Esri.ArcGISRuntime.UI.Controls">
    <Grid>
        <esriUI:MapView x:Name="MyMapView" />
        <Border Style="{StaticResource BorderStyle}">
            <StackPanel>
                <TextBlock Text="Enter an address and tap 🔎 to search."
                           IsColorFontEnabled="False"
                           TextAlignment="Center" FontWeight="SemiBold" />
                <AutoSuggestBox x:Name="AutoSuggestBox"
                                QueryIcon="Find"
                                HorizontalAlignment="Stretch"
                                Margin="0,5,0,0"
                                IsEnabled="False"
                                ItemsSource="{x:Bind _addresses}"
                                QuerySubmitted="AutoSuggestBox_OnQuerySubmitted" />
            </StackPanel>
        </Border>
    </Grid>
</UserControl>
// Copyright 2019 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 ArcGISRuntime.Samples.Managers;
using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Symbology;
using Esri.ArcGISRuntime.Tasks.Geocoding;
using Esri.ArcGISRuntime.UI;
using Esri.ArcGISRuntime.UI.Controls;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Threading.Tasks;
using Windows.UI.Popups;
using Windows.UI.Xaml.Controls;

namespace ArcGISRuntime.UWP.Samples.OfflineGeocode
{
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        "Offline geocode",
        "Search",
        "Geocode with offline data.",
        "")]
    [ArcGISRuntime.Samples.Shared.Attributes.OfflineData("1330ab96ac9c40a49e59650557f2cd63", "344e3b12368543ef84045ef9aa3c32ba")]
    public partial class OfflineGeocode
    {
        // Addresses for suggestion.
        private readonly string[] _addresses =
        {
            "910 N Harbor Dr, San Diego, CA 92101",
            "2920 Zoo Dr, San Diego, CA 92101",
            "111 W Harbor Dr, San Diego, CA 92101",
            "868 4th Ave, San Diego, CA 92101",
            "750 A St, San Diego, CA 92101"
        };

        // The LocatorTask provides geocoding services.
        private LocatorTask _geocoder;

        public OfflineGeocode()
        {
            InitializeComponent();

            // Setup the control references and execute initialization
            Initialize();
        }

        private async void Initialize()
        {
            // Get the offline tile package and use it as a basemap.
            string basemapPath = DataManager.GetDataFolder("1330ab96ac9c40a49e59650557f2cd63", "streetmap_SD.tpk");
            ArcGISTiledLayer tiledBasemapLayer = new ArcGISTiledLayer(new TileCache(basemapPath));

            // Create new Map with basemap.
            Map myMap = new Map(new Basemap(tiledBasemapLayer));

            // Provide Map to the MapView.
            MyMapView.Map = myMap;

            // Add a graphics overlay for showing pins.
            MyMapView.GraphicsOverlays.Add(new GraphicsOverlay());

            // Enable tap-for-info pattern on results.
            MyMapView.GeoViewTapped += MyMapView_GeoViewTapped;

            // Update suggestions.
            AutoSuggestBox.ItemsSource = _addresses;

            // Initialize the LocatorTask with the provided service Uri.
            try
            {
                // Get the path to the locator.
                string locatorPath = DataManager.GetDataFolder("344e3b12368543ef84045ef9aa3c32ba", "san-diego-locator.loc");

                // Load the geocoder.
                _geocoder = await LocatorTask.CreateAsync(new Uri(locatorPath));

                // Enable UI controls now that the LocatorTask is ready.
                AutoSuggestBox.IsEnabled = true;
            }
            catch (Exception e)
            {
                await new MessageDialog(e.ToString(), "Error").ShowAsync();
            }
        }

        private async void UpdateSearch()
        {
            // Get the text in the search bar.
            string enteredText = AutoSuggestBox.Text;

            // Clear existing marker.
            MyMapView.GraphicsOverlays[0].Graphics.Clear();
            MyMapView.DismissCallout();

            // Return if the textbox is empty or the geocoder isn't ready.
            if (String.IsNullOrWhiteSpace(enteredText) || _geocoder == null)
            {
                return;
            }

            try
            {
                // Get suggestions based on the input text.
                IReadOnlyList<GeocodeResult> geocodeResults = await _geocoder.GeocodeAsync(enteredText);

                // Stop if there are no suggestions.
                if (!geocodeResults.Any())
                {
                    await new MessageDialog("No results found.").ShowAsync();
                    return;
                }

                // Get the full address for the first suggestion.
                GeocodeResult firstSuggestion = geocodeResults.First();
                IReadOnlyList<GeocodeResult> addresses = await _geocoder.GeocodeAsync(firstSuggestion.Label);

                // Skip if there are no results.
                if (!addresses.Any())
                {
                    await new MessageDialog("No results found.", "No results").ShowAsync();
                    return;
                }

                // Show a graphic for the address.
                Graphic point = await GraphicForPoint(addresses.First().DisplayLocation);
                MyMapView.GraphicsOverlays[0].Graphics.Add(point);

                // Update the map extent to show the marker.
                MyMapView.SetViewpoint(new Viewpoint(addresses.First().Extent));
            }
            catch (Exception e)
            {
                await new MessageDialog(e.ToString(), "Error").ShowAsync();
            }
        }

        private async void MyMapView_GeoViewTapped(object sender, GeoViewInputEventArgs e)
        {
            try
            {
                // Clear existing callout and graphics.
                MyMapView.DismissCallout();
                MyMapView.GraphicsOverlays[0].Graphics.Clear();

                // Add a graphic for the tapped point.
                Graphic pinGraphic = await GraphicForPoint(e.Location);
                MyMapView.GraphicsOverlays[0].Graphics.Add(pinGraphic);

                // Reverse geocode to get addresses.
                ReverseGeocodeParameters parameters = new ReverseGeocodeParameters();
                parameters.ResultAttributeNames.Add("*");
                parameters.MaxResults = 1;
                IReadOnlyList<GeocodeResult> addresses = await _geocoder.ReverseGeocodeAsync(e.Location, parameters);

                // Get the first result.
                GeocodeResult address = addresses.First();

                // Use the address as the callout title.
                string calloutTitle = address.Attributes["Street"].ToString();
                string calloutDetail = address.Attributes["City"] + ", " + address.Attributes["State"] + " " + address.Attributes["ZIP"];

                // Define the callout.
                CalloutDefinition calloutBody = new CalloutDefinition(calloutTitle, calloutDetail);

                // Show the callout on the map at the tapped location.
                MyMapView.ShowCalloutForGeoElement(pinGraphic, e.Position, calloutBody);
            }
            catch (Exception ex)
            {
                await new MessageDialog(ex.ToString(), "Error").ShowAsync();
            }
        }

        private void AutoSuggestBox_OnQuerySubmitted(AutoSuggestBox sender, AutoSuggestBoxQuerySubmittedEventArgs args)
        {
            if (args.ChosenSuggestion != null)
            {
                AutoSuggestBox.Text = args.ChosenSuggestion.ToString();
            }
            UpdateSearch();
        }

        private async Task<Graphic> GraphicForPoint(MapPoint point)
        {
            // Get current assembly that contains the image.
            Assembly currentAssembly = GetType().GetTypeInfo().Assembly;

            // Get image as a stream from the resources.
            // Picture is defined as EmbeddedResource and DoNotCopy.
            Stream resourceStream = currentAssembly.GetManifestResourceStream(
                "ArcGISRuntime.Resources.PictureMarkerSymbols.pin_star_blue.png");

            // Create new symbol using asynchronous factory method from stream.
            PictureMarkerSymbol pinSymbol = await PictureMarkerSymbol.CreateAsync(resourceStream);
            pinSymbol.Width = 60;
            pinSymbol.Height = 60;
            // The image is a pin; offset the image so that the pinpoint
            //     is on the point rather than the image's true center.
            pinSymbol.LeaderOffsetX = 30;
            pinSymbol.OffsetY = 14;
            return new Graphic(point, pinSymbol);
        }
    }
}