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ArcGIS Runtime SDK for .NET

Identify graphics

This code sample is available for these platforms:
View Sample on GitHub

Display an alert message when a graphic is clicked.

Image of identify graphics

Use case

A user may wish to select a graphic on a map to view relevant information about it.

How to use the sample

Select a graphic to identify it. You will see an alert message displayed.

How it works

  1. Create a GraphicsOverlay and add it to the MapView.
  2. Add a Graphic along with a SimpleFillSymbol to the graphics overlay.
  3. Create a Point from the location clicked on the map view by the user.
  4. Identify the graphic on the map view with IdentifyGraphicsOverlayAsync(graphicsOverlay, pointClicked, tolerance, max results).

Relevant API

  • Graphic
  • GraphicsOverlay
  • MapView


graphics, identify

Sample Code

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns=""
    <esriUI:MapView x:Name="MyMapView"/>
// 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:
// 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 Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Symbology;
using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.UI;
using Xamarin.Forms;
using Esri.ArcGISRuntime.Data;
using Colors = System.Drawing.Color;

namespace ArcGISRuntime.Samples.IdentifyGraphics
        name: "Identify graphics",
        category: "GraphicsOverlay",
        description: "Display an alert message when a graphic is clicked.",
        instructions: "Select a graphic to identify it. You will see an alert message displayed.",
        tags: new[] { "graphics", "identify" })]
    public partial class IdentifyGraphics : ContentPage
        // Graphics overlay to host graphics
        private GraphicsOverlay _polygonOverlay;

        public IdentifyGraphics()

            // Create the UI, setup the control references and execute initialization 

        private void Initialize()
            // Create a map with 'Imagery with Labels' basemap and an initial location
            Map myMap = new Map(Basemap.CreateTopographic());

            // Create graphics overlay with graphics

            // Hook into tapped event
            MyMapView.GeoViewTapped += OnMapViewTapped;

            // Assign the map to the MapView
            MyMapView.Map = myMap;

        private void CreateOverlay()
            // Create polygon builder and add polygon corners into it
            PolygonBuilder builder = new PolygonBuilder(SpatialReferences.WebMercator);
            builder.AddPoint(new MapPoint(-20e5, 20e5));
            builder.AddPoint(new MapPoint(20e5, 20e5));
            builder.AddPoint(new MapPoint(20e5, -20e5));
            builder.AddPoint(new MapPoint(-20e5, -20e5));

            // Get geometry from the builder
            Polygon polygonGeometry = builder.ToGeometry();

            // Create symbol for the polygon
            SimpleFillSymbol polygonSymbol = new SimpleFillSymbol(

            // Create new graphic
            Graphic polygonGraphic = new Graphic(polygonGeometry, polygonSymbol);

            // Create overlay to where graphics are shown
            _polygonOverlay = new GraphicsOverlay();
            // Add created overlay to the MapView

        private async void OnMapViewTapped(object sender, Esri.ArcGISRuntime.Xamarin.Forms.GeoViewInputEventArgs e)
            double tolerance = 10d; // Use larger tolerance for touch
            int maximumResults = 1; // Only return one graphic  
            bool onlyReturnPopups = false; // Don't return only popups

                // Use the following method to identify graphics in a specific graphics overlay
                IdentifyGraphicsOverlayResult identifyResults = await MyMapView.IdentifyGraphicsOverlayAsync(

                // Check if we got results
                if (identifyResults.Graphics.Count > 0)
                    // Make sure that the UI changes are done in the UI thread
                    Device.BeginInvokeOnMainThread(async () => {
                        await Application.Current.MainPage.DisplayAlert("", "Tapped on graphic", "OK");
            catch (Exception ex)
                await Application.Current.MainPage.DisplayAlert("Error", ex.ToString(), "OK");