Due to the limited screen size of some mobile devices, it may be difficult to identify individual features on a map where there is a high density of information, or the scale is very small. This can be the case when a mobile device is used for navigation, and the user wishes to magnify a particular area to better identify a road intersection.
How to use the sample
Tap and hold on the map to show a magnifier, then drag across the map to move the magnifier. You can also pan the map while holding the magnifier, by dragging the magnifier to the edge of the map.
How it works
Create a new MapView, and add an Map to it.
Enable the magnifier using mapView.MagnifierEnabled. This will set the magnifier to be shown on the Map when the user performs a long press gesture. Note: The default value is false.
Relevant API
Map
MapView
MapView.MagnifierEnabled
Additional information
This sample only works on a device with a touch screen. The magnifier will not appear via a mouse click.
Tags
magnify, map, zoom
Sample Code
ShowMagnifier.cs
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// 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.Mapping;
using Esri.ArcGISRuntime.UI.Controls;
namespaceArcGISRuntime.Samples.ShowMagnifier{
[Activity (ConfigurationChanges=Android.Content.PM.ConfigChanges.Orientation | Android.Content.PM.ConfigChanges.ScreenSize)]
[ArcGISRuntime.Samples.Shared.Attributes.Sample(
name: "Show magnifier",
category: "MapView",
description: "Tap and hold on a map to show a magnifier.",
instructions: "Tap and hold on the map to show a magnifier, then drag across the map to move the magnifier. You can also pan the map while holding the magnifier, by dragging the magnifier to the edge of the map.",
tags: new[] { "magnify", "map", "zoom" })]
publicclassShowMagnifier : Activity {
// Hold a reference to the map viewprivate MapView _myMapView;
protectedoverridevoidOnCreate(Bundle bundle) {
base.OnCreate(bundle);
Title = "Show magnifier";
// Create the UI, setup the control references and execute initialization CreateLayout();
Initialize();
}
privatevoidInitialize() {
// Create new Map with basemap and initial location Map myMap = new Map(BasemapType.Topographic, 34.056295, -117.195800, 10);
// Enable the ability to interact with the map view (including enabling the magnifier) _myMapView.InteractionOptions = new Esri.ArcGISRuntime.UI.MapViewInteractionOptions
{
// Enable magnifier IsMagnifierEnabled = true };
// Assign the map to the MapView _myMapView.Map = myMap;
}
privatevoidCreateLayout() {
// Create a new vertical layout for the app LinearLayout layout = new LinearLayout(this) { Orientation = Orientation.Vertical };
// Create and add a help label TextView helpLabel = new TextView(this)
{
Text = "Tap and hold to show the magnifier. Note: This only works on touchscreen devices." };
layout.AddView(helpLabel);
// Add the map view to the layout _myMapView = new MapView(this);
layout.AddView(_myMapView);
// Show the layout in the app SetContentView(layout);
}
}
}