Display the map at an initial viewpoint representing a bounding geometry.
Use case
Setting the initial viewpoint is useful when a user wishes to first load the map at a particular area of interest.
How to use the sample
When the sample loads, note that the map view opens at the initial viewpoint defined on the map.
How it works
- Instantiate a
Map
object. - Instantiate a
Viewpoint
object using anEnvelope
object. - Set the starting location of the map with
map.InitialViewpoint
. - Set the map in the
MapView
.
Relevant API
- Envelope
- Map
- MapView
- Point
- Viewpoint
Tags
extent, envelope, initial, viewpoint, zoom
Sample Code
// Copyright 2016 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.UI.Controls;
namespace ArcGISRuntime.Samples.SetInitialMapArea
{
[Activity (ConfigurationChanges=Android.Content.PM.ConfigChanges.Orientation | Android.Content.PM.ConfigChanges.ScreenSize)]
[ArcGISRuntime.Samples.Shared.Attributes.Sample(
name: "Map initial extent",
category: "Map",
description: "Display the map at an initial viewpoint representing a bounding geometry.",
instructions: "When the sample loads, note that the map view opens at the initial viewpoint defined on the map.",
tags: new[] { "envelope", "extent", "initial", "viewpoint", "zoom" })]
public class SetInitialMapArea : Activity
{
// Hold a reference to the map view
private MapView _myMapView;
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
Title = "Set initial map area";
// Create the UI, setup the control references and execute initialization
CreateLayout();
Initialize();
}
private void Initialize()
{
// Create new Map with basemap
Map myMap = new Map(BasemapStyle.ArcGISImageryStandard);
// Create and set initial map area
Envelope initialLocation = new Envelope(
-12211308.778729, 4645116.003309, -12208257.879667, 4650542.535773,
SpatialReferences.WebMercator);
myMap.InitialViewpoint = new Viewpoint(initialLocation);
// Provide used Map to the MapView
_myMapView.Map = myMap;
}
private void CreateLayout()
{
// Create a new vertical layout for the app
LinearLayout layout = new LinearLayout(this) { Orientation = Orientation.Vertical };
// Add the map view to the layout
_myMapView = new MapView(this);
layout.AddView(_myMapView);
// Show the layout in the app
SetContentView(layout);
}
}
}