Rotate a map.
Use case
A user may wish to view the map in an orientation other than north-facing.
How to use the sample
Use the slider to rotate the map.
How it works
- Instantiate an
Map
object. - Set the map in the
MapView
object. - Use
SetViewpointRotationAsync
to indicate the rotation angle.
Relevant API
- Map
- Compass
- MapView
Tags
rotate, rotation, viewpoint
Sample Code
MapRotation.cs
// 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.Views;
using Android.Widget;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.UI.Controls;
namespace ArcGISRuntime.Samples.MapRotation
{
[Activity (ConfigurationChanges=Android.Content.PM.ConfigChanges.Orientation | Android.Content.PM.ConfigChanges.ScreenSize)]
[ArcGISRuntime.Samples.Shared.Attributes.Sample(
name: "Map rotation",
category: "MapView",
description: "Rotate a map.",
instructions: "Use the slider to rotate the map.",
tags: new[] { "rotate", "rotation", "viewpoint" })]
public class MapRotation : Activity
{
// Hold a reference to the map view
private MapView _myMapView;
private TextView _mapRotationLabel;
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
CreateLayout();
Initialize();
Title = "Map rotation";
}
private void Initialize()
{
// Create a new Map instance with the basemap
Basemap myBasemap = new Basemap(BasemapStyle.ArcGISStreets);
_myMapView.Map = new Map(myBasemap);
}
private void CreateLayout()
{
LinearLayout layout = new LinearLayout(this) { Orientation = Orientation.Vertical };
// Create a slider (SeekBar) control for selecting an angle
SeekBar angleSlider = new SeekBar(this)
{
// Set a maximum slider value (minimum is always 0)
Max = 360,
Progress = 0
};
// When the slider value (Progress) changes, rotate the map
angleSlider.ProgressChanged += (s, e) =>
{
if (e.FromUser)
{
// Set rotation asynchronously (no need to await the result)
_myMapView.SetViewpointRotationAsync(e.Progress);
// Display the MapView's rotation.
_mapRotationLabel.Text = $"{angleSlider.Progress:0}°";
}
};
// Create a layout to show the slider and label
LinearLayout sliderLayout = new LinearLayout(this)
{
Orientation = Orientation.Horizontal
};
sliderLayout.SetPadding(10, 10, 10, 10);
angleSlider.LayoutParameters = new LinearLayout.LayoutParams(
ViewGroup.LayoutParams.MatchParent,
ViewGroup.LayoutParams.MatchParent,
1.0f
);
_mapRotationLabel = new TextView(this);
_mapRotationLabel.SetMaxWidth(150);
_mapRotationLabel.SetMinWidth(150);
sliderLayout.AddView(angleSlider);
sliderLayout.AddView(_mapRotationLabel);
// Display the MapView's initial rotation value.
_mapRotationLabel.Text = $"{angleSlider.Progress:0}°";
// Add the controls to the view
layout.AddView(sliderLayout);
_myMapView = new MapView(this);
layout.AddView(_myMapView);
// Apply the layout to the app
SetContentView(layout);
}
}
}