Change basemap

View inWPFUWPFormsiOSAndroid
View on GitHub

Change a map's basemap. A basemap is beneath all layers on a Map and is used to provide visual reference for the operational layers.

Image of change basemap

Use case

Basemaps should be selected contextually. For example, in maritime applications, it would be more appropriate to use a basemap of the world's oceans as opposed to a basemap of the world's streets.

How to use the sample

Use the drop down menu to select the active basemap from the list of available basemaps.

How it works

  1. Create an Map object.
  2. Set the map to the MapView object.
  3. Choose a new basemap type and set it on the map.

Relevant API

  • Basemap
  • Map
  • MapView

Tags

basemap, map

Sample Code

ChangeBasemap.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
// 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 System;
using System.Collections.Generic;
using System.Linq;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.UI.Controls;
using Foundation;
using UIKit;

namespace ArcGISRuntime.Samples.ChangeBasemap
{
    [Register("ChangeBasemap")]
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        name: "Change basemap",
        category: "Map",
        description: "Change a map's basemap. A basemap is beneath all layers on a `Map` and is used to provide visual reference for the operational layers.",
        instructions: "Use the drop down menu to select the active basemap from the list of available basemaps.",
        tags: new[] { "basemap", "map" })]
    public class ChangeBasemap : UIViewController
    {
        // Hold references to UI controls.
        private MapView _myMapView;
        private UIBarButtonItem _changeBasemapButton;

        // Dictionary that associates names with basemaps.
        private readonly Dictionary<string, Basemap> _basemapOptions = new Dictionary<string, Basemap>()
        {
            {"Streets", new Basemap(BasemapStyle.ArcGISStreets)},
            {"Streets - Night", new Basemap(BasemapStyle.ArcGISStreetsNight)},
            {"Imagery", new Basemap(BasemapStyle.ArcGISImageryStandard)},
            {"Imagery with Labels", new Basemap(BasemapStyle.ArcGISImagery)},
            {"Dark Gray Canvas", new Basemap(BasemapStyle.ArcGISDarkGray)},
            {"Light Gray Canvas", new Basemap(BasemapStyle.ArcGISLightGray)},
            {"Navigation", new Basemap(BasemapStyle.ArcGISNavigation)},
            {"OpenStreetMap", new Basemap(BasemapStyle.OSMStandard)}
        };

        public ChangeBasemap()
        {
            Title = "Change basemap";
        }

        private void BasemapSelectionButtonClick(object sender, EventArgs e)
        {
            // Create the view controller that will present the list of basemaps.
            UIAlertController basemapSelectionAlert = UIAlertController.Create("Select a basemap", "", UIAlertControllerStyle.ActionSheet);

            // Add an option for each basemap.
            foreach (string item in _basemapOptions.Keys)
            {
                // Selecting a basemap will call the lambda method, which will apply the chosen basemap.
                basemapSelectionAlert.AddAction(UIAlertAction.Create(item, UIAlertActionStyle.Default, action => _myMapView.Map.Basemap = _basemapOptions[item]));
            }

            // Fix to prevent crash on iPad.
            var popoverPresentationController = basemapSelectionAlert.PopoverPresentationController;
            if (popoverPresentationController != null)
            {
                popoverPresentationController.BarButtonItem = (UIBarButtonItem) sender;
            }

            // Show the alert.
            PresentViewController(basemapSelectionAlert, true, null);
        }

        private void Initialize()
        {
            // Create and use a new map.
            _myMapView.Map = new Map(_basemapOptions.Values.First());
        }

        public override void ViewDidLoad()
        {
            base.ViewDidLoad();
            Initialize();
        }

        public override void LoadView()
        {
            // Create the views.
            View = new UIView {BackgroundColor = ApplicationTheme.BackgroundColor};

            _myMapView = new MapView();
            _myMapView.TranslatesAutoresizingMaskIntoConstraints = false;

            _changeBasemapButton = new UIBarButtonItem();
            _changeBasemapButton.Title = "Change basemap";

            UIToolbar toolbar = new UIToolbar();
            toolbar.TranslatesAutoresizingMaskIntoConstraints = false;
            toolbar.Items = new[]
            {
                new UIBarButtonItem(UIBarButtonSystemItem.FlexibleSpace),
                _changeBasemapButton,
                new UIBarButtonItem(UIBarButtonSystemItem.FlexibleSpace)
            };

            // Add the views.
            View.AddSubviews(_myMapView, toolbar);

            // Lay out the views.
            NSLayoutConstraint.ActivateConstraints(new[]
            {
                _myMapView.TopAnchor.ConstraintEqualTo(View.SafeAreaLayoutGuide.TopAnchor),
                _myMapView.LeadingAnchor.ConstraintEqualTo(View.LeadingAnchor),
                _myMapView.TrailingAnchor.ConstraintEqualTo(View.TrailingAnchor),
                _myMapView.BottomAnchor.ConstraintEqualTo(toolbar.TopAnchor),

                toolbar.BottomAnchor.ConstraintEqualTo(View.SafeAreaLayoutGuide.BottomAnchor),
                toolbar.LeadingAnchor.ConstraintEqualTo(View.LeadingAnchor),
                toolbar.TrailingAnchor.ConstraintEqualTo(View.TrailingAnchor)
            });
        }

        public override void ViewWillAppear(bool animated)
        {
            base.ViewWillAppear(animated);

            // Subscribe to events.
            _changeBasemapButton.Clicked += BasemapSelectionButtonClick;
        }

        public override void ViewDidDisappear(bool animated)
        {
            base.ViewDidDisappear(animated);

            // Unsubscribe from events, per best practice.
            _changeBasemapButton.Clicked -= BasemapSelectionButtonClick;
        }
    }
}

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