Set the map view to a new viewpoint.
Use case
Programatically navigate to a specified location in the map or scene. Use this to focus on a particular point or area of interest.
How to use the sample
The map view has several methods for setting its current viewpoint. Select a viewpoint from the UI to see the viewpoint changed using that method.
How it works
- Create a new
Map
object and set it to theMapView
object. - Change the map's
Viewpoint
using one of the available methods:
- Use
MapView.SetViewpointAsync()
to pan to a viewpoint. - Use
MapView.SetViewpointCenterAsync()
to center the viewpoint on aPoint
. - Use
MyMapView.SetViewpointScaleAsync()
to set a distance from the ground using a scale. - Use
MapView.SetViewpointGeometryAsync()
to set the viewpoint to a givenGeometry
.
Relevant API
- Geometry
- Map
- MapView
- Point
- Viewpoint
Additional information
Below are some other ways to set a viewpoint:
- SetViewpoint
- SetViewpointAsync
- SetViewpointCenterAsync
- SetViewpointGeometryAsync
- SetViewpointRotationAsync
- SetViewpointScaleAsync
Tags
animate, extent, pan, rotate, scale, view, zoom
Sample Code
ChangeViewpoint.cs
// Copyright 2018 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.Views;
using Android.Widget;
using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.UI.Controls;
using System;
using System.Collections.Generic;
using System.Linq;
namespace ArcGISRuntime.Samples.ChangeViewpoint
{
[Activity (ConfigurationChanges=Android.Content.PM.ConfigChanges.Orientation | Android.Content.PM.ConfigChanges.ScreenSize)]
[ArcGISRuntime.Samples.Shared.Attributes.Sample(
name: "Change viewpoint",
category: "MapView",
description: "Set the map view to a new viewpoint.",
instructions: "The map view has several methods for setting its current viewpoint. Select a viewpoint from the UI to see the viewpoint changed using that method.",
tags: new[] { "animate", "extent", "pan", "rotate", "scale", "view", "zoom" })]
public class ChangeViewpoint : Activity
{
// Create and hold reference to the used MapView
private MapView _myMapView;
// Coordinates for London
private readonly MapPoint _londonCoords = new MapPoint(-13881.7678417696, 6710726.57374296, SpatialReferences.WebMercator);
private const double LondonScale = 8762.7156655228955;
// Coordinates for Redlands
private readonly Polygon _redlandsPolygon = new Polygon(
new List<MapPoint>
{
new MapPoint(-13049785.1566222, 4032064.6003424),
new MapPoint(-13049785.1566222, 4040202.42595729),
new MapPoint(-13037033.5780234, 4032064.6003424),
new MapPoint(-13037033.5780234, 4040202.42595729)
},
SpatialReferences.WebMercator);
// Coordinates for Edinburgh
private readonly Polygon _edinburghPolygon = new Polygon(
new List<MapPoint>
{
new MapPoint(-354262.156621384, 7548092.94093301),
new MapPoint(-354262.156621384, 7548901.50684376),
new MapPoint(-353039.164455303, 7548092.94093301),
new MapPoint(-353039.164455303, 7548901.50684376)},
SpatialReferences.WebMercator);
// String array to store titles for the viewpoints specified above.
private readonly string[] _titles = {
"Geometry",
"Center & Scale",
"Animate"
};
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
Title = "Change viewpoint";
// Create the UI, setup the control references and execute initialization
CreateLayout();
Initialize();
}
private void Initialize()
{
// Create new Map with basemap and initial location
Map myMap = new Map(BasemapStyle.ArcGISTopographic);
// Assign the map to the MapView
_myMapView.Map = myMap;
}
private void OnMapsClicked(object sender, EventArgs e)
{
Button viewpointsButton = (Button)sender;
// Create menu to show viewpoint options
PopupMenu mapsMenu = new PopupMenu(this, viewpointsButton);
mapsMenu.MenuItemClick += OnViewpointMenuItemClicked;
// Create menu options
foreach (string title in _titles)
{
mapsMenu.Menu.Add(title);
}
// Show menu in the view
mapsMenu.Show();
}
private async void OnViewpointMenuItemClicked(object sender, PopupMenu.MenuItemClickEventArgs e)
{
try
{
// Get title from the selected item
string selectedMapTitle = e.Item.TitleCondensedFormatted.ToString();
switch (selectedMapTitle)
{
case "Geometry":
// Set Viewpoint using Redlands envelope defined above and a padding of 20
await _myMapView.SetViewpointGeometryAsync(_redlandsPolygon, 20);
break;
case "Center & Scale":
// Set Viewpoint so that it is centered on the London coordinates defined above
await _myMapView.SetViewpointCenterAsync(_londonCoords);
// Set the Viewpoint scale to match the specified scale
await _myMapView.SetViewpointScaleAsync(LondonScale);
break;
case "Animate":
// Navigate to full extent of the first baselayer before animating to specified geometry
await _myMapView.SetViewpointAsync(
new Viewpoint(_myMapView.Map.Basemap.BaseLayers.First().FullExtent));
// Create a new Viewpoint using the specified geometry
Viewpoint viewpoint = new Viewpoint(_edinburghPolygon);
// Set Viewpoint of MapView to the Viewpoint created above and animate to it using a timespan of 5 seconds
await _myMapView.SetViewpointAsync(viewpoint, TimeSpan.FromSeconds(5));
break;
default:
break;
}
}
catch (Exception ex)
{
new AlertDialog.Builder(this).SetMessage(ex.ToString()).SetTitle("Error").Show();
}
}
private void CreateLayout()
{
// Create a new vertical layout for the app
LinearLayout layout = new LinearLayout(this) { Orientation = Orientation.Vertical };
// Create button to show possible map options
Button mapsButton = new Button(this)
{
Text = "Change viewpoint"
};
mapsButton.Click += OnMapsClicked;
// Add maps button to the layout
layout.AddView(mapsButton);
// Add the map view to the layout
_myMapView = new MapView(this);
layout.AddView(_myMapView);
// Show the layout in the app
SetContentView(layout);
}
}
}