Find place

View inWPFUWPFormsiOSAndroid
View on GitHub

Find places of interest near a location or within a specific area.

Image of find place

Use case

When getting directions or looking for nearby places, users may only know what the place has ("food"), the type of place ("gym"), or the generic place name ("Starbucks"), rather than the specific address. You can get suggestions and locations for these places of interest (POIs) using a natural language query. Additionally, you can filter the results to a specific area.

How to use the sample

Choose a type of place in the first field and an area to search within in the second field. Tap the Search button to show the results of the query on the map. Tap on a result pin to show its name and address. If you pan away from the result area, a "Redo search in this area" button will appear. Tap it to query again for the currently viewed area on the map.

How it works

  1. Create a LocatorTask using a URL to a locator service.
  2. Find the location for an address (or city name) to build an envelope to search within:

    • Create GeocodeParameters.
    • Add return fields to the parameters' ResultAttributeNames collection. Only add a single "*" option to return all fields.
    • Call locatorTask.GeocodeAsync(locationQueryString, geocodeParameters) to get a list of GeocodeResults.
    • Use the DisplayLocation from one of the results to build an Envelope to search within.
  3. Get place of interest (POI) suggestions based on a place name query:

    • Create SuggestParameters.
    • Add "POI" to the parameters' categories collection.
    • Call locatorTask.SuggestAsync(placeQueryString, suggestParameters) to get a list of SuggestResults.
    • The SuggestResult will have a label to display in the search suggestions list.
  4. Use one of the suggestions or a user-written query to find the locations of POIs:

    • Create GeocodeParameters.
    • Set the parameters' searchArea to the envelope.
    • Call locatorTask.GeocodeAsync(suggestionLabelOrPlaceQueryString, geocodeParameters) to get a list of GeocodeResults.
    • Display the places of interest using the results' DisplayLocations.

About the data

This sample uses the Geocoding service.

Relevant API

  • GeocodeParameters
  • GeocodeResult
  • LocatorTask
  • SuggestParameters
  • SuggestResult

Tags

businesses, geocode, locations, locator, places of interest, POI, point of interest, search, suggestions

Sample Code

FindPlace.cs
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
// 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 Android;
using Android.App;
using Android.Content.PM;
using Android.OS;
using Android.Support.V4.App;
using Android.Support.V4.Content;
using Android.Views;
using Android.Widget;
using Esri.ArcGISRuntime.Data;
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 Google.Android.Material.Snackbar;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Threading.Tasks;

namespace ArcGISRuntime.Samples.FindPlace
{
    [Activity(ConfigurationChanges = Android.Content.PM.ConfigChanges.Orientation | Android.Content.PM.ConfigChanges.ScreenSize)]
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        name: "Find place",
        category: "Search",
        description: "Find places of interest near a location or within a specific area.",
        instructions: "Choose a type of place in the first field and an area to search within in the second field. Tap the Search button to show the results of the query on the map. Tap on a result pin to show its name and address. If you pan away from the result area, a \"Redo search in this area\" button will appear. Tap it to query again for the currently viewed area on the map.",
        tags: new[] { "POI", "businesses", "geocode", "locations", "locator", "places of interest", "point of interest", "search", "suggestions" })]
    [ArcGISRuntime.Samples.Shared.Attributes.EmbeddedResource(@"PictureMarkerSymbols\pin_star_blue.png")]
    public partial class FindPlace : Activity
    {
        // The LocatorTask provides geocoding services via a service.
        private LocatorTask _geocoder;

        // Service Uri to be provided to the LocatorTask (geocoder).
        private Uri _serviceUri = new Uri("https://geocode.arcgis.com/arcgis/rest/services/World/GeocodeServer");

        // Hold references to the UI controls.
        private MapView _myMapView;
        private AutoCompleteTextView _mySearchBox;
        private AutoCompleteTextView _myLocationBox;
        private Button _mySearchButton;
        private Button _mySearchRestrictedButton;
        private ProgressBar _myProgressBar;

        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            Title = "Find place";

            CreateLayout();
            Initialize();
        }

        private async void Initialize()
        {
            // Create new Map with basemap.
            Map myMap = new Map(BasemapStyle.ArcGISStreets);

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

            // Wire up the map view to support tapping on address markers.
            _myMapView.GeoViewTapped += _myMapView_GeoViewTapped;

            // Ask for location permissions. Events wired up in OnRequestPermissionsResult.
            AskForLocationPermission();

            // Initialize the LocatorTask with the provided service Uri.
            _geocoder = await LocatorTask.CreateAsync(_serviceUri);

            // Enable controls now that the geocoder is ready.
            _mySearchBox.Enabled = true;
            _myLocationBox.Enabled = true;
            _mySearchButton.Enabled = true;
            _mySearchRestrictedButton.Enabled = true;
        }

        private void LocationDisplay_LocationChanged(object sender, Esri.ArcGISRuntime.Location.Location e)
        {
            // Return if no location.
            if (e.Position == null)
            {
                return;
            }

            // Unsubscribe; only want to zoom to location once.
            ((LocationDisplay)sender).LocationChanged -= LocationDisplay_LocationChanged;
            RunOnUiThread(() => { _myMapView.SetViewpoint(new Viewpoint(e.Position, 10000)); });
        }

        private void CreateLayout()
        {
            // Vertical stack layout.
            LinearLayout layout = new LinearLayout(this) { Orientation = Orientation.Vertical };

            // Search bar.
            _mySearchBox = new AutoCompleteTextView(this) { Text = "Coffee" };
            layout.AddView(_mySearchBox);

            // Location search bar.
            _myLocationBox = new AutoCompleteTextView(this) { Text = "Current Location" };
            layout.AddView(_myLocationBox);

            // Disable multi-line searches.
            _mySearchBox.SetMaxLines(1);
            _myLocationBox.SetMaxLines(1);

            // Search buttons; horizontal layout.
            LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(
                ViewGroup.LayoutParams.MatchParent,
                ViewGroup.LayoutParams.MatchParent,
                1.0f
            );
            LinearLayout searchButtonLayout = new LinearLayout(this) { Orientation = Orientation.Horizontal };
            _mySearchButton = new Button(this) { Text = "Search All", LayoutParameters = param };
            _mySearchRestrictedButton = new Button(this) { Text = "Search View", LayoutParameters = param };

            // Add the buttons to the layout.
            searchButtonLayout.AddView(_mySearchButton);
            searchButtonLayout.AddView(_mySearchRestrictedButton);

            // Progress bar.
            _myProgressBar = new ProgressBar(this) { Indeterminate = true, Visibility = Android.Views.ViewStates.Gone };
            layout.AddView(_myProgressBar);

            // Add the layout to the view.
            layout.AddView(searchButtonLayout);

            // Add the mapview to the view.
            _myMapView = new MapView(this);
            layout.AddView(_myMapView);

            // Show the layout in the app.
            SetContentView(layout);

            // Disable the buttons and search bar until the geocoder is ready.
            _mySearchBox.Enabled = false;
            _myLocationBox.Enabled = false;
            _mySearchButton.Enabled = false;
            _mySearchRestrictedButton.Enabled = false;

            // Hook up the UI event handlers for suggestion & search.
            _mySearchBox.TextChanged += _mySearchBox_TextChanged;
            _myLocationBox.TextChanged += _myLocationBox_TextChanged;
            _mySearchButton.Click += _mySearchButton_Click;
            _mySearchRestrictedButton.Click += _mySearchRestrictedButton_Click;
        }

        private async Task<MapPoint> GetSearchMapPoint(string locationText)
        {
            // Get the map point for the search text.
            if (locationText != "Current Location")
            {
                // Geocode the location.
                IReadOnlyList<GeocodeResult> locations = await _geocoder.GeocodeAsync(locationText);

                // return if there are no results.
                if (!locations.Any())
                {
                    return null;
                }

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

                // Return the map point.
                return result.DisplayLocation;
            }
            else
            {
                // Get the current device location.
                return _myMapView.LocationDisplay.Location.Position;
            }
        }

        private async Task UpdateSearch(string enteredText, string locationText, bool restrictToExtent = false)
        {
            // Clear any existing markers.
            _myMapView.GraphicsOverlays.Clear();

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

            // Create the geocode parameters.
            GeocodeParameters parameters = new GeocodeParameters();

            // Get the MapPoint for the current search location.
            MapPoint searchLocation = await GetSearchMapPoint(locationText);

            // Update the geocode parameters if the map point is not null.
            if (searchLocation != null)
            {
                parameters.PreferredSearchLocation = searchLocation;
            }

            // Update the search area if desired.
            if (restrictToExtent)
            {
                // Get the current map extent.
                Geometry extent = _myMapView.VisibleArea;

                // Update the search parameters.
                parameters.SearchArea = extent;
            }

            // Show the progress bar.
            _myProgressBar.Visibility = Android.Views.ViewStates.Visible;

            // Get the location information.
            IReadOnlyList<GeocodeResult> locations = await _geocoder.GeocodeAsync(enteredText, parameters);

            // Stop gracefully and show a message if the geocoder does not return a result.
            if (locations.Count < 1)
            {
                _myProgressBar.Visibility = Android.Views.ViewStates.Gone; // 1. Hide the progress bar.
                ShowMessage("No results found", "Alert"); // 2. Show a message.
                return; // 3. Stop.
            }

            // Create the GraphicsOverlay so that results can be drawn on the map.
            GraphicsOverlay resultOverlay = new GraphicsOverlay();

            // Add each address to the map.
            foreach (GeocodeResult location in locations)
            {
                // Get the Graphic to display.
                Graphic point = await GraphicForPoint(location.DisplayLocation);

                // Add the specific result data to the point.
                point.Attributes["Match_Title"] = location.Label;

                // Get the address for the point.
                IReadOnlyList<GeocodeResult> addresses = await _geocoder.ReverseGeocodeAsync(location.DisplayLocation);

                // Add the first suitable address if possible.
                if (addresses.Any())
                {
                    point.Attributes["Match_Address"] = addresses.First().Label;
                }

                // Add the Graphic to the GraphicsOverlay.
                resultOverlay.Graphics.Add(point);
            }

            // Hide the progress bar.
            _myProgressBar.Visibility = Android.Views.ViewStates.Gone;

            // Add the GraphicsOverlay to the MapView.
            _myMapView.GraphicsOverlays.Add(resultOverlay);

            // Update the map viewpoint.
            await _myMapView.SetViewpointGeometryAsync(resultOverlay.Extent, 50);
        }

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

            // 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);
        }

        private async void _myMapView_GeoViewTapped(object sender, GeoViewInputEventArgs e)
        {
            // Search for the graphics underneath the user's tap.
            IReadOnlyList<IdentifyGraphicsOverlayResult> results = await _myMapView.IdentifyGraphicsOverlaysAsync(e.Position, 12, false);

            // Clear callouts and return if there was no result.
            if (results.Count < 1 || results.First().Graphics.Count < 1)
            {
                _myMapView.DismissCallout();
                return;
            }

            // Get the first graphic from the first result.
            Graphic matchingGraphic = results.First().Graphics.First();

            // Get the title; manually added to the point's attributes in UpdateSearch.
            string title = matchingGraphic.Attributes["Match_Title"] as string;

            // Get the address; manually added to the point's attributes in UpdateSearch.
            string address = matchingGraphic.Attributes["Match_Address"] as string;

            // Define the callout.
            CalloutDefinition calloutBody = new CalloutDefinition(title, address);

            // Show the callout on the map at the tapped location.
            _myMapView.ShowCalloutAt(e.Location, calloutBody);
        }

        private async Task<List<string>> GetSuggestResults(string searchText, string location = "", bool poiOnly = false)
        {
            // Quit if string is null, empty, or whitespace.
            if (String.IsNullOrWhiteSpace(searchText))
            {
                return new List<string>();
            }

            // Quit if the geocoder isn't ready.
            if (_geocoder == null)
            {
                return new List<string>();
            }

            // Create geocode parameters.
            SuggestParameters parameters = new SuggestParameters();

            // Restrict suggestions to points of interest if desired.
            if (poiOnly)
            {
                parameters.Categories.Add("POI");
            }

            // Set the location for the suggest parameters.
            if (!String.IsNullOrWhiteSpace(location))
            {
                // Get the MapPoint for the current search location.
                MapPoint searchLocation = await GetSearchMapPoint(location);

                // Update the geocode parameters if the map point is not null.
                if (searchLocation != null)
                {
                    parameters.PreferredSearchLocation = searchLocation;
                }
            }

            // Get the updated results from the query so far.
            IReadOnlyList<SuggestResult> results = await _geocoder.SuggestAsync(searchText, parameters);

            // Return the list.
            return results.Select(result => result.Label).ToList();
        }

        private async void _mySearchBox_TextChanged(object sender, Android.Text.TextChangedEventArgs e)
        {
            // Dismiss callout, if any.
            UserInteracted();

            // Get the current text.
            string searchText = _mySearchBox.Text;

            // Get the current search location.
            string locationText = _myLocationBox.Text;

            // Convert the list into a usable format for the suggest box.
            List<string> results = await GetSuggestResults(searchText, locationText, true);

            // Quit if there are no results.
            if (!results.Any())
            {
                return;
            }

            // Create an array adapter to provide autocomplete suggestions.
            ArrayAdapter adapter = new ArrayAdapter(this, Android.Resource.Layout.SimpleSpinnerItem, results);

            // Apply the adapter.
            _mySearchBox.Adapter = adapter;
        }

        private async void _myLocationBox_TextChanged(object sender, Android.Text.TextChangedEventArgs e)
        {
            // Dismiss callout, if any.
            UserInteracted();

            // Get the current text.
            string searchText = _myLocationBox.Text;

            // Get the results.
            List<string> results = await GetSuggestResults(searchText);

            // Quit if there are no results.
            if (!results.Any())
            {
                return;
            }

            // Add a 'current location' option to the list.
            results.Insert(0, "Current Location");

            // Create an array adapter to provide autocomplete suggestions.
            ArrayAdapter adapter = new ArrayAdapter(this, Android.Resource.Layout.SimpleSpinnerItem, results);

            // Apply the adapter.
            _myLocationBox.Adapter = adapter;
        }

        private async void _mySearchButton_Click(object sender, EventArgs e)
        {
            // Dismiss callout, if any.
            UserInteracted();

            // Get the search text.
            string searchText = _mySearchBox.Text;

            // Get the location text.
            string locationText = _myLocationBox.Text;

            // Run the search.
            await UpdateSearch(searchText, locationText);
        }

        private async void _mySearchRestrictedButton_Click(object sender, EventArgs e)
        {
            // Dismiss callout, if any.
            UserInteracted();

            // Get the search text.
            string searchText = _mySearchBox.Text;

            // Get the location text.
            string locationText = _myLocationBox.Text;

            // Run the search.
            await UpdateSearch(searchText, locationText, true);
        }

        private void UserInteracted()
        {
            // Hide the callout.
            _myMapView.DismissCallout();
        }

        private void ShowMessage(string message, string title = "Error") => new AlertDialog.Builder(this).SetTitle(title).SetMessage(message).Show();

        protected override void OnDestroy()
        {
            // Stop the location data source.
            _myMapView?.LocationDisplay?.DataSource?.StopAsync();

            base.OnDestroy();
        }
    }

    #region Location Display Permissions

    public partial class FindPlace : ActivityCompat.IOnRequestPermissionsResultCallback
    {
        private const int LocationPermissionRequestCode = 99;

        private async void AskForLocationPermission()
        {
            // Only check if permission hasn't been granted yet.
            if (ContextCompat.CheckSelfPermission(this, LocationService) != Permission.Granted)
            {
                // The Fine location permission will be requested.
                var requiredPermissions = new[] { Manifest.Permission.AccessFineLocation };

                // Only prompt the user first if the system says to.
                if (ActivityCompat.ShouldShowRequestPermissionRationale(this, Manifest.Permission.AccessFineLocation))
                {
                    // A snackbar is a small notice that shows on the bottom of the view.
                    Snackbar.Make(_myMapView,
                            "Location permission is needed to display location on the map.",
                            Snackbar.LengthIndefinite)
                        .SetAction("OK",
                            delegate
                            {
                                // When the user presses 'OK', the system will show the standard permission dialog.
                                // Once the user has accepted or denied, OnRequestPermissionsResult is called with the result.
                                ActivityCompat.RequestPermissions(this, requiredPermissions, LocationPermissionRequestCode);
                            }
                        ).Show();
                }
                else
                {
                    // When the user presses 'OK', the system will show the standard permission dialog.
                    // Once the user has accepted or denied, OnRequestPermissionsResult is called with the result.
                    this.RequestPermissions(requiredPermissions, LocationPermissionRequestCode);
                }
            }
            else
            {
                try
                {
                    // Explicit DataSource.LoadAsync call is used to surface any errors that may arise.
                    await _myMapView.LocationDisplay.DataSource.StartAsync();
                    _myMapView.LocationDisplay.IsEnabled = true;
                    _myMapView.LocationDisplay.LocationChanged += LocationDisplay_LocationChanged;
                }
                catch (Exception ex)
                {
                    System.Diagnostics.Debug.WriteLine(ex);
                    ShowMessage(ex.Message, "Failed to start location display.");
                }
            }
        }

        public override async void OnRequestPermissionsResult(int requestCode, string[] permissions, Permission[] grantResults)
        {
            // Ignore other location requests.
            if (requestCode != LocationPermissionRequestCode)
            {
                return;
            }

            // If the permissions were granted, enable location.
            if (grantResults.Length == 1 && grantResults[0] == Permission.Granted)
            {
                System.Diagnostics.Debug.WriteLine("User affirmatively gave permission to use location. Enabling location.");
                try
                {
                    // Explicit DataSource.LoadAsync call is used to surface any errors that may arise.
                    await _myMapView.LocationDisplay.DataSource.StartAsync();
                    _myMapView.LocationDisplay.IsEnabled = true;
                    _myMapView.LocationDisplay.LocationChanged += LocationDisplay_LocationChanged;
                }
                catch (Exception ex)
                {
                    System.Diagnostics.Debug.WriteLine(ex);
                    ShowMessage(ex.Message, "Failed to start location display.");
                }
            }
            else
            {
                ShowMessage("Location permissions not granted.", "Failed to start location display.");
            }
        }
    }

    #endregion Location Display Permissions
}

Your browser is no longer supported. Please upgrade your browser for the best experience. See our browser deprecation post for more details.