Generate offline map

View inWPFUWPFormsiOSAndroid
View on GitHub

Take a web map offline.

Image of generate offline map

Use case

Taking a web map offline allows users continued productivity when their network connectivity is poor or nonexistent. For example, by taking a map offline, a field worker inspecting utility lines in remote areas could still access a feature's location and attribute information.

How to use the sample

When the app starts, you will be prompted to sign in using a free ArcGIS Online account. Once the map loads, zoom to the extent you want to take offline. The red border shows the extent that will be downloaded. Tap the "Take Map Offline" button to start the offline map job. The progress bar will show the job's progress. When complete, the offline map will replace the online map in the map view.

How it works

  1. Create an Map with a Portal item pointing to the web map.
  2. Create GenerateOfflineMapParameters specifying the download area geometry, minimum scale, and maximum scale.
  3. Create an OfflineMapTask with the map.
  4. Create the OfflineMapJob with OfflineMapTask.GenerateOfflineMap(params, downloadDirectoryPath) and start it with OfflineMapJob.Start().
  5. When the job is done, get the offline map with OfflineMapJob.Result.OfflineMap.

Relevant API

  • GenerateOfflineMapJob
  • GenerateOfflineMapParameters
  • GenerateOfflineMapResult
  • OfflineMapTask
  • Portal

About the data

The map used in this sample shows the stormwater network within Naperville, IL, USA, with cartography designed for web and mobile devices with offline support.

Additional information

The creation of the offline map can be fine-tuned using parameter overrides for feature layers, or by using local basemaps to achieve more customized results.

Tags

download, offline, save, web map

Sample Code

GenerateOfflineMap.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
// Copyright 2021 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.App;
using Android.OS;
using Android.Widget;
using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Portal;
using Esri.ArcGISRuntime.Symbology;
using Esri.ArcGISRuntime.Tasks;
using Esri.ArcGISRuntime.Tasks.Offline;
using Esri.ArcGISRuntime.UI;
using Esri.ArcGISRuntime.UI.Controls;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;

namespace ArcGISRuntime.Samples.GenerateOfflineMap
{
    [Activity(ConfigurationChanges = Android.Content.PM.ConfigChanges.Orientation | Android.Content.PM.ConfigChanges.ScreenSize)]
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        name: "Generate offline map",
        category: "Map",
        description: "Take a web map offline.",
        instructions: "When the app starts, you will be prompted to sign in using a free ArcGIS Online account. Once the map loads, zoom to the extent you want to take offline. The red border shows the extent that will be downloaded. Tap the \"Take Map Offline\" button to start the offline map job. The progress bar will show the job's progress. When complete, the offline map will replace the online map in the map view.",
        tags: new[] { "download", "offline", "save", "web map" })]
    public class GenerateOfflineMap : Activity
    {
        // Mapview.
        private MapView _mapView;

        // Generate Button.
        private Button _takeMapOfflineButton;

        // Progress indicator.
        private AlertDialog _alertDialog;
        private ProgressBar _progressIndicator;

        // The job to generate an offline map.
        private GenerateOfflineMapJob _generateOfflineMapJob;

        // The extent of the data to take offline.
        private Envelope _areaOfInterest = new Envelope(-88.1541, 41.7690, -88.1471, 41.7720, SpatialReferences.Wgs84);

        // The ID for a web map item hosted on the server (water network map of Naperville IL).
        private string WebMapId = "acc027394bc84c2fb04d1ed317aac674";

        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);
            Title = "Generate offline map";

            // Create the UI, setup the control references and execute initialization.
            CreateLayout();
            Initialize();
        }

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

            // Add the generate button.
            _takeMapOfflineButton = new Button(this)
            {
                Text = "Take map offline"
            };
            _takeMapOfflineButton.Click += TakeMapOfflineButton_Click;
            layout.AddView(_takeMapOfflineButton);

            // Add the mapview.
            _mapView = new MapView(this);
            layout.AddView(_mapView);

            // Add the layout to the view.
            SetContentView(layout);

            // Create the progress dialog display.
            _progressIndicator = new ProgressBar(this);
            _progressIndicator.SetProgress(40, true);
            AlertDialog.Builder builder = new AlertDialog.Builder(this).SetView(_progressIndicator);
            builder.SetCancelable(true);
            builder.SetMessage("Generating offline map ...");
            _alertDialog = builder.Create();
            _alertDialog.SetButton("Cancel", (s, e) =>
            {
                _generateOfflineMapJob.Cancel();
            });
        }

        private async void Initialize()
        {
            try
            {
                // Create the ArcGIS Online portal.
                ArcGISPortal portal = await ArcGISPortal.CreateAsync();

                // Get the Naperville water web map item using its ID.
                PortalItem webmapItem = await PortalItem.CreateAsync(portal, WebMapId);

                // Create a map from the web map item.
                Map onlineMap = new Map(webmapItem);

                // Display the map in the MapView.
                _mapView.Map = onlineMap;

                // Disable user interactions on the map (no panning or zooming from the initial extent).
                _mapView.InteractionOptions = new MapViewInteractionOptions
                {
                    IsEnabled = false
                };

                // Create a graphics overlay for the extent graphic and apply a renderer.
                SimpleLineSymbol aoiOutlineSymbol = new SimpleLineSymbol(SimpleLineSymbolStyle.Solid, System.Drawing.Color.Red, 3);
                GraphicsOverlay extentOverlay = new GraphicsOverlay
                {
                    Renderer = new SimpleRenderer(aoiOutlineSymbol)
                };
                _mapView.GraphicsOverlays.Add(extentOverlay);

                // Add a graphic to show the area of interest (extent) that will be taken offline.
                Graphic aoiGraphic = new Graphic(_areaOfInterest);
                extentOverlay.Graphics.Add(aoiGraphic);
            }
            catch (Exception ex)
            {
                // Show the exception message to the user.
                ShowStatusMessage(ex.Message);
            }
        }

        private async void TakeMapOfflineButton_Click(object sender, EventArgs e)
        {
            // Create a path for the output mobile map.
            string tempPath = $"{Path.GetTempPath()}";
            string[] outputFolders = Directory.GetDirectories(tempPath, "NapervilleWaterNetwork*");

            // Loop through the folder names and delete them.
            foreach (string dir in outputFolders)
            {
                try
                {
                    // Delete the folder.
                    Directory.Delete(dir, true);
                }
                catch (Exception)
                {
                    // Ignore exceptions (files might be locked, for example).
                }
            }

            // Create a new folder for the output mobile map.
            string packagePath = Path.Combine(tempPath, @"NapervilleWaterNetwork");
            int num = 1;
            while (Directory.Exists(packagePath))
            {
                packagePath = Path.Combine(tempPath, @"NapervilleWaterNetwork" + num.ToString());
                num++;
            }

            // Create the output directory.
            Directory.CreateDirectory(packagePath);

            try
            {
                // Show the progress dialog while the job is running.
                _alertDialog.Show();

                // Create an offline map task with the current (online) map.
                OfflineMapTask takeMapOfflineTask = await OfflineMapTask.CreateAsync(_mapView.Map);

                // Create the default parameters for the task, pass in the area of interest.
                GenerateOfflineMapParameters parameters = await takeMapOfflineTask.CreateDefaultGenerateOfflineMapParametersAsync(_areaOfInterest);

                // Create the job with the parameters and output location.
                _generateOfflineMapJob = takeMapOfflineTask.GenerateOfflineMap(parameters, packagePath);

                // Handle the progress changed event for the job.
                _generateOfflineMapJob.ProgressChanged += OfflineMapJob_ProgressChanged;

                // Await the job to generate geodatabases, export tile packages, and create the mobile map package.
                GenerateOfflineMapResult results = await _generateOfflineMapJob.GetResultAsync();

                // Check for job failure (writing the output was denied, e.g.).
                if (_generateOfflineMapJob.Status != JobStatus.Succeeded)
                {
                    // Report failure to the user.
                    ShowStatusMessage("Failed to take the map offline.");
                }

                // Check for errors with individual layers.
                if (results.LayerErrors.Any())
                {
                    // Build a string to show all layer errors.
                    System.Text.StringBuilder errorBuilder = new System.Text.StringBuilder();
                    foreach (KeyValuePair<Layer, Exception> layerError in results.LayerErrors)
                    {
                        errorBuilder.AppendLine(string.Format("{0} : {1}", layerError.Key.Id, layerError.Value.Message));
                    }

                    // Show layer errors.
                    ShowStatusMessage(errorBuilder.ToString());
                }

                // Display the offline map.
                _mapView.Map = results.OfflineMap;

                // Apply the original viewpoint for the offline map.
                _mapView.SetViewpoint(new Viewpoint(_areaOfInterest));

                // Enable map interaction so the user can explore the offline data.
                _mapView.InteractionOptions.IsEnabled = true;

                // Change the title and disable the "Take map offline" button.
                _takeMapOfflineButton.Text = "Map is offline";
                _takeMapOfflineButton.Enabled = false;
            }
            catch (TaskCanceledException)
            {
                // Generate offline map task was canceled.
                ShowStatusMessage("Taking map offline was canceled");
            }
            catch (Exception ex)
            {
                // Exception while taking the map offline.
                ShowStatusMessage(ex.Message);
            }
            finally
            {
                // Hide the loading overlay when the job is done.
                _alertDialog.Dismiss();
            }
        }

        private void ShowStatusMessage(string message)
        {
            // Display the message to the user.
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.SetMessage(message).SetTitle("Alert").Show();
        }

        // Show changes in job progress.
        private void OfflineMapJob_ProgressChanged(object sender, EventArgs e)
        {
            // Get the job.
            GenerateOfflineMapJob job = sender as GenerateOfflineMapJob;

            // Dispatch to the UI thread.
            RunOnUiThread(() =>
            {
                // Show the percent complete and update the progress bar.
                string percentText = job.Progress > 0 ? job.Progress.ToString() + " %" : string.Empty;
                _progressIndicator.Progress = job.Progress;
                _alertDialog.SetMessage($"Taking map offline ({percentText}) ...");
            });
        }
    }
}

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