Find a route and directions

Learn how to find a route and directions with the route service.

Routing is the process of finding the path from an origin to a destination in a street network. You can use the Routing service to find routes, get driving directions, calculate drive times, and solve complicated, multiple vehicle routing problems. To create a route, you typically define a set of stops (origin and one or more destinations) and use the service to find a route with directions. You can also use a number of additional parameters such as barriers and mode of travel to refine the results.

In this tutorial, you define an origin and destination by clicking on the map. These values are used to get a route and directions from the route service. The directions are also displayed on the map.

Prerequisites

Before starting this tutorial:

You need an ArcGIS Location Platform or ArcGIS Online account.
Ensure your development environment meets the system requirements.

Optionally, you may want to install the ArcGIS Maps SDK for .NET to get access to project templates in Visual Studio (Windows only) and offline copies of the NuGet packages.

Set up authentication

To access the secure ArcGIS location services used in this tutorial, you must implement API key authentication or user authentication using an ArcGIS Location Platform or an ArcGIS Online account.

You can implement API key authentication or user authentication in this tutorial. Compare the differences below:

API key authentication

Users are not required to sign in.
Requires creating an API key credential with the correct privileges.
API keys are long-lived access tokens.
Service usage is billed to the API key owner/developer.
Simplest authentication method to implement.
Recommended approach for new ArcGIS developers.

Learn more in API key authentication.

User authentication

Users are required to sign in with an ArcGIS account.
User accounts must have privilege to access the ArcGIS services used in application.
Requires creating OAuth credentials.
Application uses a redirect URL and client ID.
Service usage is billed to the organization of the user signed into the application.

Learn more in User authentication.

Create a new API key access token with privileges to access the secure resources used in this tutorial.

Complete the Create an API key tutorial and create an API key with the following privilege(s):
- Privileges
  - Location services > Basemaps
  - Location services > Routing
Copy and paste the API key access token into a safe location. It will be used in a later step.

Create new OAuth credentials to access the secure resources used in this tutorial.

Complete the Create OAuth credentials for user authentication tutorial to obtain a Client ID and Redirect URL.

A Client ID uniquely identifies your app on the authenticating server. If the server cannot find an app with the provided Client ID, it will not proceed with authentication.
The Redirect URL (also referred to as a callback url) is used to identify a response from the authenticating server when the system returns control back to your app after an OAuth login. Since it does not necessarily represent a valid endpoint that a user could navigate to, the redirect URL can use a custom scheme, such as my-app://auth. It is important to make sure the redirect URL used in your app's code matches a redirect URL configured on the authenticating server.
Copy and paste the Client ID and Redirect URL into a safe location. They will be used in a later step.

All users that access this application need account privileges to access the basemap styles service and the ArcGIS routing service.

Develop or download

You have two options for completing this tutorial:

Option 1: Develop the code or
Option 2: Download the completed solution

Option 1: Develop the code

To start the tutorial, complete the Display a map tutorial. This creates a map to display the Santa Monica Mountains in California using the topographic basemap from the ArcGIS basemap styles service.

Open a Visual Studio solution

Open the Visual Studio solution you created by completing the Display a map tutorial.
Continue with the following instructions to find a route and directions with the ArcGIS routing service.

Update the tutorial name used in the project (optional)

The Visual Studio solution, project, and the namespace for all classes currently use the name DisplayAMap. Follow the steps below if you prefer the name to reflect the current tutorial. These steps are not required, your code will still work if you keep the original name.

The tutorial instructions and code use the name FindARouteAndDirections for the solution, project, and namespace. You can choose any name you like, but it should be the same for each of these.

Update the name for the solution and the project.
- In Visual Studio, in the Solution Explorer, right-click the solution name and choose Rename. Provide the new name for your solution.
- In the Solution Explorer, right-click the project name and choose Rename. Provide the new name for your project.
Rename the namespace used by classes in the project.
- In the Solution Explorer, expand the project node.
- Double-click MapViewModel.cs in the Solution Explorer to open the file.
- In the MapViewModel class, double-click the namespace name (DisplayAMap) to select it, and then right-click and choose Rename....
- Provide the new name for the namespace.
- Click Apply in the Rename: DisplayAMap window that appears in the upper-right of the code window. This will rename the namespace throughout your project.
Build the project.
- Choose Build > Build solution (or press <F6>).

Set developer credentials

If you implemented API key authentication in the Display a map tutorial, the API key access token will only have the Basemaps privilege. The Find a route and directions tutorial requires the Routing privilege to find a route using the RouteTask. To create an API Key access token that has the Basemaps and Routing privileges, see the Set up authentication step and then follow the instructions below.

In the Solution Explorer, expand the node for App.xaml, and double-click App.xaml.cs to open it.

In the App class, in the override for the OnStartup() function, set the ApiKey property on ArcGISRuntimeEnvironment with your new API key (with additional privileges besides basemap).

App.xaml.cs
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    public partial class App : Application
    {

        protected override void OnStartup(StartupEventArgs e)
        {
            base.OnStartup(e);

            // Set the access token for ArcGIS Maps SDK for .NET.
            Esri.ArcGISRuntime.ArcGISRuntimeEnvironment.ApiKey = "YOUR_ACCESS_TOKEN";

        }

    }
}

Save and close the App.xaml.cs file.

Best Practice: The access token is stored directly in the code as a convenience for this tutorial. Do not store credentials directly in source code in a production environment.

From the Visual Studio Project menu, choose Add class .... Name the class ArcGISLoginPrompt.cs then click Add. The new class is added to your project and opens in Visual Studio.
Select all the code in the new class and delete it.

Copy all of the code below and paste it into the ArcGISLoginPrompt.cs class in your project.

ArcGISLoginPrompt.cs
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// 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 Esri.ArcGISRuntime.Security;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Navigation;
using System.Windows.Threading;

namespace UserAuth
{

    internal static class ArcGISLoginPrompt
    {
        private const string ArcGISOnlineUrl = "https://www.arcgis.com/sharing/rest";
        // Specify the Client ID and Redirect URL to use with OAuth authentication.
        // See the instructions here for creating OAuth app settings:
        // https://developers.arcgis.com/documentation/security-and-authentication/user-authentication/tutorials/create-oauth-credentials-user-auth/

        private const string AppClientId = "YOUR_CLIENT_ID";
        private const string OAuthRedirectUrl = "YOUR_REDIRECT_URL";

        public static async Task<bool> EnsureAGOLCredentialAsync()
        {
            bool loggedIn = false;

            try
            {
                // Create a challenge request for portal credentials (OAuth credential request for arcgis.com)
                CredentialRequestInfo challengeRequest = new CredentialRequestInfo
                {
                    // Use the OAuth authorization code workflow.
                    GenerateTokenOptions = new GenerateTokenOptions
                    {
                        TokenAuthenticationType = TokenAuthenticationType.OAuthAuthorizationCode
                    },

                    // Indicate the url (portal) to authenticate with (ArcGIS Online)
                    ServiceUri = new Uri(ArcGISOnlineUrl)
                };

                // Call GetCredentialAsync on the AuthenticationManager to invoke the challenge handler
                Credential? cred = await AuthenticationManager.Current.GetCredentialAsync(challengeRequest, false);
                loggedIn = cred != null;
            }
            catch (OperationCanceledException)
            {
                // OAuth login was canceled, no need to display error to user.
            }
            catch (Exception ex)
            {
                // Login failure
                MessageBox.Show("Login failed: " + ex.Message);
            }

            return loggedIn;
        }

        public static void SetChallengeHandler()
        {
            var userConfig = new OAuthUserConfiguration(new Uri(ArcGISOnlineUrl), AppClientId, new Uri(OAuthRedirectUrl));
            AuthenticationManager.Current.OAuthUserConfigurations.Add(userConfig);
            AuthenticationManager.Current.OAuthAuthorizeHandler = new OAuthAuthorize();
        }

        #region OAuth handler

        // In a desktop (WPF) app, an IOAuthAuthorizeHandler component is used to handle some of the OAuth details. Specifically, it
        //     implements AuthorizeAsync to show the login UI (generated by the server that hosts secure content) in a web control.
        //     When the user logs in successfully, cancels the login, or closes the window without continuing, the IOAuthAuthorizeHandler
        //     is responsible for obtaining the authorization from the server or raising an OperationCanceledException.
        public class OAuthAuthorize : IOAuthAuthorizeHandler
        {
            // Window to contain the OAuth UI.
            private Window? _authWindow;

            // Use a TaskCompletionSource to track the completion of the authorization.
            private TaskCompletionSource<IDictionary<string, string>> _tcs;

            // URL for the authorization callback result (the redirect URI configured for your application).
            private string _callbackUrl = "";

            // URL that handles the OAuth request.
            private string? _authorizeUrl;

            // Function to handle authorization requests, takes the URIs for the secured service, the authorization endpoint, and the redirect URI.
            public Task<IDictionary<string, string>> AuthorizeAsync(Uri serviceUri, Uri authorizeUri, Uri callbackUri)
            {
                if (_tcs != null && !_tcs.Task.IsCompleted)
                    throw new Exception("Task in progress");

                _tcs = new TaskCompletionSource<IDictionary<string, string>>();

                // Store the authorization and redirect URLs.
                _authorizeUrl = authorizeUri.AbsoluteUri;
                _callbackUrl = callbackUri.AbsoluteUri;

                // Call a function to show the login controls, make sure it runs on the UI thread for this app.
                Dispatcher dispatcher = Application.Current.Dispatcher;
                if (dispatcher == null || dispatcher.CheckAccess())
                {
                    AuthorizeOnUIThread(_authorizeUrl);
                }
                else
                {
                    Action authorizeOnUIAction = () => AuthorizeOnUIThread(_authorizeUrl);
                    dispatcher.BeginInvoke(authorizeOnUIAction);
                }

                // Return the task associated with the TaskCompletionSource.
                return _tcs.Task;
            }

            // Challenge for OAuth credentials on the UI thread.
            private void AuthorizeOnUIThread(string authorizeUri)
            {
                // Create a WebBrowser control to display the authorize page.
                WebBrowser webBrowser = new WebBrowser();

                // Handle the navigation event for the browser to check for a response to the redirect URL.
                webBrowser.Navigating += WebBrowserOnNavigating;

                // Display the web browser in a new window.
                _authWindow = new Window
                {
                    Content = webBrowser,
                    Width = 450,
                    Height = 450,
                    WindowStartupLocation = WindowStartupLocation.CenterOwner
                };

                // Set the app's window as the owner of the browser window (if main window closes, so will the browser).
                if (Application.Current != null && Application.Current.MainWindow != null)
                {
                    _authWindow.Owner = Application.Current.MainWindow;
                }

                // Handle the window closed event then navigate to the authorize url.
                _authWindow.Closed += OnWindowClosed;
                webBrowser.Navigate(authorizeUri);

                // Display the window.
                _authWindow.ShowDialog();
            }

            // Handle the browser window closing.
            private void OnWindowClosed(object? sender, EventArgs e)
            {
                // If the browser window closes, return the focus to the main window.
                if (_authWindow != null && _authWindow.Owner != null)
                {
                    _authWindow.Owner.Focus();
                }

                // If the task wasn't completed, the user must have closed the window without logging in.
                if (!_tcs.Task.IsCompleted)
                {
                    // Set the task completion source exception to indicate a canceled operation.
                    _tcs.SetCanceled();
                }

                _authWindow = null;
            }

            // Handle browser navigation (content changing).
            private void WebBrowserOnNavigating(object sender, NavigatingCancelEventArgs e)
            {
                // Check for a response to the callback url.
                const string portalApprovalMarker = "/oauth2/approval";
                WebBrowser? webBrowser = sender as WebBrowser;

                Uri uri = e.Uri;

                // If no browser, uri, or an empty url, return.
                if (webBrowser == null || uri == null || string.IsNullOrEmpty(uri.AbsoluteUri))
                    return;

                // Check for redirect.
                bool isRedirected = uri.AbsoluteUri.StartsWith(_callbackUrl) ||
                    _callbackUrl.Contains(portalApprovalMarker) && uri.AbsoluteUri.Contains(portalApprovalMarker);

                // Check if browser was redirected to the callback URL. (This indicates succesful authentication.)
                if (isRedirected)
                {
                    e.Cancel = true;

                    // Call a helper function to decode the response parameters.
                    IDictionary<string, string> authResponse = DecodeParameters(uri);

                    // Set the result for the task completion source.
                    _tcs.SetResult(authResponse);

                    // Close the window.
                    if (_authWindow != null)
                    {
                        _authWindow.Close();
                    }
                }
            }

            private static IDictionary<string, string> DecodeParameters(Uri uri)
            {
                // Create a dictionary of key value pairs returned in an OAuth authorization response URI query string.
                string answer = "";

                // Get the values from the URI fragment or query string.
                if (!string.IsNullOrEmpty(uri.Fragment))
                {
                    answer = uri.Fragment.Substring(1);
                }
                else
                {
                    if (!string.IsNullOrEmpty(uri.Query))
                    {
                        answer = uri.Query.Substring(1);
                    }
                }

                // Parse parameters into key / value pairs.
                Dictionary<string, string> keyValueDictionary = new Dictionary<string, string>();
                string[] keysAndValues = answer.Split(new[] { '&' }, StringSplitOptions.RemoveEmptyEntries);
                foreach (string kvString in keysAndValues)
                {
                    string[] pair = kvString.Split('=');
                    string key = pair[0];
                    string value = string.Empty;
                    if (key.Length > 1)
                    {
                        value = Uri.UnescapeDataString(pair[1]);
                    }

                    keyValueDictionary.Add(key, value);
                }

                // Return the dictionary of string keys/values.
                return keyValueDictionary;
            }
        }

        #endregion OAuth handler
    }
}

Add your values for the client ID (AppClientId) and for the redirect URL (OAuthRedirectUrl). These are the user authentication settings you created in the Set up authentication step.

ArcGISLoginPrompt.cs
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    internal static class ArcGISLoginPrompt
    {
        private const string ArcGISOnlineUrl = "https://www.arcgis.com/sharing/rest";
        // Specify the Client ID and Redirect URL to use with OAuth authentication.
        // See the instructions here for creating OAuth app settings:
        // https://developers.arcgis.com/documentation/security-and-authentication/user-authentication/tutorials/create-oauth-credentials-user-auth/

        private const string AppClientId = "YOUR_CLIENT_ID";
        private const string OAuthRedirectUrl = "YOUR_REDIRECT_URL";

In the Solution Explorer, expand the node for App.xaml, and double-click App.xaml.cs to open it.

In the App class, in the override for the OnStartup() function, call the SetChallengeHandler() method on your static ArcGISLoginPrompt class.

App.xaml.cs
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    public partial class App : Application
    {

        protected override void OnStartup(StartupEventArgs e)
        {
            base.OnStartup(e);

            // Call a function to set up the AuthenticationManager for OAuth.
            UserAuth.ArcGISLoginPrompt.SetChallengeHandler();

        }

    }
}

Save and close the App.xaml.cs file.

Best Practice: The OAuth credentials are stored directly in the code as a convenience for this tutorial. Do not store credentials directly in source code in a production environment.

Update the basemap and initial extent

For displaying routes and driving directions, a streets basemap usually works best. You will update the Map to use the ArcGISStreets basemap and center the display on Los Angeles, California.

In the Visual Studio > Solution Explorer, double-click MapViewModel.cs to open the file.

In the SetupMap() function, update the Map to use the BasemapStyle.ArcGISStreets basemap.

MapViewModel.cs
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        private void SetupMap()
        {

            var map = new Map(BasemapStyle.ArcGISStreets);

Update the Viewpoint that the MapView shows when the map initializes. This viewpoint will show an area around Los Angeles, California.

MapViewModel.cs
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        private void SetupMap()
        {

            var map = new Map(BasemapStyle.ArcGISStreets);

            // Set the initial viewpoint around the Santa Monica Mountains in California.

            var mapCenterPoint = new MapPoint(-118.24532, 34.05398, SpatialReferences.Wgs84);

            map.InitialViewpoint = new Viewpoint(mapCenterPoint, 100000);

Click Debug > Start Debugging (or press <F5> on the keyboard) to run the app. If your app uses user authentication, enter your ArcGIS Online credentials when prompted.

You should see a streets map centered on an area of Los Angeles.

Define member variables

You will need member variables in the MapViewModel class to store the status of user-defined route stops and several Graphic objects for displaying route results.

Add additional required using statements to the top of the MapViewModel class.

Classes in the Esri.ArcGISRuntime.Tasks.NetworkAnalysis namespace provide network analysis functionality, such as solving routes, finding closest facilities, or defining service areas on a street network. Esri.ArcGISRuntime.UI contains the Graphic and GraphicsOverlay classes. Esri.ArcGISRuntime.Symbology contains the classes that define the symbols and renderers used to display features and graphics.

MapViewModel.cs
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using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using System.Text;
using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;

using System.Linq;
using System.Threading.Tasks;
using Esri.ArcGISRuntime.Symbology;
using Esri.ArcGISRuntime.Tasks.NetworkAnalysis;
using Esri.ArcGISRuntime.UI;

Create the enum with values that represent the three possible contexts for clicks on the map. Add a private variable to track the current click state.

The user will click the map to define the origin and destination locations for the route. If neither stop has been defined, a map click will be used for the origin ("from") location. If an origin is defined, the click will be used to define the destination ("to") location. If both are defined, you may choose to start over and use the click to define a new origin location. This enum has values that represent the context of these clicks so the code can respond appropriately.

MapViewModel.cs
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namespace FindARouteAndDirections
{
    class MapViewModel : INotifyPropertyChanged
    {

        enum RouteBuilderStatus
        {
            NotStarted, // No locations have been defined.
            SelectedStart, // Origin point exists.
            SelectedStartAndEnd // Origin and destination exist.
        }
        private RouteBuilderStatus _currentState = RouteBuilderStatus.NotStarted;
Expand

Create additional member variables for the route result graphics. These graphics will show the stops (origin and destination locations) and the route result polyline that connects them.

MapViewModel.cs
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        enum RouteBuilderStatus
        {
            NotStarted, // No locations have been defined.
            SelectedStart, // Origin point exists.
            SelectedStartAndEnd // Origin and destination exist.
        }
        private RouteBuilderStatus _currentState = RouteBuilderStatus.NotStarted;

        private Graphic _startGraphic = new();
        private Graphic _endGraphic = new();
        private Graphic _routeGraphic = new();
Expand

Add properties for graphics overlays and driving directions

A graphics overlay is a container for graphics that are always displayed on top of all the other layers in the map. You will use graphics overlays to display graphics for a Route and its stops.

A Route provides turn-by-turn directions with its DirectionManeuvers property. You will expose the directions with a property in MapViewModel so they can be bound to a control in the app's UI.

In the view model, create a new property named GraphicsOverlays. This will be a collection of GraphicsOverlay that will store point, line, and polygon graphics.

MapViewModel.cs
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        private Map? _map;
        public Map? Map
        {
            get { return _map; }
            set
            {
                _map = value;
                OnPropertyChanged();
            }
        }

        private GraphicsOverlayCollection? _graphicsOverlayCollection;
        public GraphicsOverlayCollection? GraphicsOverlays
        {
            get { return _graphicsOverlayCollection; }
            set
            {
                _graphicsOverlayCollection = value;
                OnPropertyChanged();
            }
        }
Expand

Create a property in MapViewModel that exposes a list of driving directions for a Route.

MapViewModel.cs
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        private GraphicsOverlayCollection? _graphicsOverlayCollection;
        public GraphicsOverlayCollection? GraphicsOverlays
        {
            get { return _graphicsOverlayCollection; }
            set
            {
                _graphicsOverlayCollection = value;
                OnPropertyChanged();
            }
        }

        private List<string>? _directions;
        public List<string>? Directions
        {
            get { return _directions; }
            set
            {
                _directions = value;
                OnPropertyChanged();
            }
        }
Expand

Create route graphics

You will define the symbology for each Route result Graphic and add them to a GraphicsOverlay.

Create a new GraphicsOverlay to contain graphics for the Route result and stops. Create a GraphicsOverlayCollection that contains the overlay and use it to set the MapViewModel.GraphicsOverlays property.

MapViewModel.cs
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        private void SetupMap()
        {

            var map = new Map(BasemapStyle.ArcGISStreets);

            // Set the initial viewpoint around the Santa Monica Mountains in California.

            var mapCenterPoint = new MapPoint(-118.24532, 34.05398, SpatialReferences.Wgs84);

            map.InitialViewpoint = new Viewpoint(mapCenterPoint, 100000);

            GraphicsOverlay routeAndStopsOverlay = new GraphicsOverlay();
            this.GraphicsOverlays = new GraphicsOverlayCollection
            {
                routeAndStopsOverlay
            };
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Create each result Graphic and define its Symbol.

The Geometry for each graphic is initially null and will not display until a valid geometry is assigned (for example, when the user clicks to define a stop location).

MapViewModel.cs
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            GraphicsOverlay routeAndStopsOverlay = new GraphicsOverlay();
            this.GraphicsOverlays = new GraphicsOverlayCollection
            {
                routeAndStopsOverlay
            };

            var startOutlineSymbol = new SimpleLineSymbol(SimpleLineSymbolStyle.Solid, System.Drawing.Color.Blue, 2);
            _startGraphic = new Graphic(null, new SimpleMarkerSymbol
                {
                    Style = SimpleMarkerSymbolStyle.Diamond,
                    Color = System.Drawing.Color.Orange,
                    Size = 8,
                    Outline = startOutlineSymbol
                }
            );

            var endOutlineSymbol = new SimpleLineSymbol(style: SimpleLineSymbolStyle.Solid, color: System.Drawing.Color.Red, width: 2);
            _endGraphic = new Graphic(null, new SimpleMarkerSymbol
                {
                    Style = SimpleMarkerSymbolStyle.Square,
                    Color = System.Drawing.Color.Green,
                    Size = 8,
                    Outline = endOutlineSymbol
                }
            );

            _routeGraphic = new Graphic(null, new SimpleLineSymbol(
                style: SimpleLineSymbolStyle.Solid,
                color: System.Drawing.Color.Blue,
                width: 4
            ));
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Add the graphics to the GraphicsOverlay.

MapViewModel.cs
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            _routeGraphic = new Graphic(null, new SimpleLineSymbol(
                style: SimpleLineSymbolStyle.Solid,
                color: System.Drawing.Color.Blue,
                width: 4
            ));

            routeAndStopsOverlay.Graphics.AddRange(new [] { _startGraphic, _endGraphic, _routeGraphic });
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Create a function to reset the current route creation state. The function will set the Geometry for each result Graphic to null, clear driving directions text from the MapViewModel.Directions property, and set the status variable to RouteBuilderStatus.NotStarted.

MapViewModel.cs
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            routeAndStopsOverlay.Graphics.AddRange(new [] { _startGraphic, _endGraphic, _routeGraphic });

            // Set the view model's Map property with the map.
            Map = map;
        }

        private void ResetState()
        {
            _startGraphic.Geometry = null;
            _endGraphic.Geometry = null;
            _routeGraphic.Geometry = null;
            Directions = null;
            _currentState = RouteBuilderStatus.NotStarted;
        }
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Find a route between two stops

You will create a function that uses the route service to find the best route between two stops.

Create a new asynchronous function called FindRoute().

When calling methods asynchronously inside a function (using the await keyword), the async keyword is required in the signature.

Asynchronous functions that don't return a value should have a return type of Task. Although a void return type would continue to work, this is not considered best practice. Exceptions thrown by an async void method cannot be caught outside of that method, are difficult to test, and can cause serious side effects if the caller is not expecting them to be asynchronous. The only circumstance where async void is acceptable is when using an event handler, such as a button click.

See the Microsoft documentation for more information about Asynchronous programming with async and await.

MapViewModel.cs
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        private void ResetState()
        {
            _startGraphic.Geometry = null;
            _endGraphic.Geometry = null;
            _routeGraphic.Geometry = null;
            Directions = null;
            _currentState = RouteBuilderStatus.NotStarted;
        }

        public async Task FindRoute()
        {

        }
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Create route Stop objects using the start and end graphics' geometry.

MapViewModel.cs
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        public async Task FindRoute()
        {

            if(_startGraphic.Geometry == null || _endGraphic.Geometry == null) return;
            var stops = new [] { _startGraphic, _endGraphic }.Select(graphic =>
            {
                var geometry = graphic.Geometry as MapPoint;
                return new Stop(geometry!);
            });
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Create a new RouteTask that uses the route service. Create RouteParameters, SetStops and request to ReturnRoutes and ReturnDirections with the result.

MapViewModel.cs
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            if(_startGraphic.Geometry == null || _endGraphic.Geometry == null) return;
            var stops = new [] { _startGraphic, _endGraphic }.Select(graphic =>
            {
                var geometry = graphic.Geometry as MapPoint;
                return new Stop(geometry!);
            });

            var routeTask = await RouteTask.CreateAsync(new Uri("https://route-api.arcgis.com/arcgis/rest/services/World/Route/NAServer/Route_World"));

            RouteParameters parameters = await routeTask.CreateDefaultParametersAsync();
            parameters.SetStops(stops);
            parameters.ReturnDirections = true;
            parameters.ReturnRoutes = true;
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Use the RouteTask to solve the route. If the RouteResult contains a Route, set the route graphic geometry with the result geometry, set the MapViewModel.Directions property with the DirectionManeuvers, and reset the current state. If no route was found, reset the state and throw an exception to alert the user.

MapViewModel.cs
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            var routeTask = await RouteTask.CreateAsync(new Uri("https://route-api.arcgis.com/arcgis/rest/services/World/Route/NAServer/Route_World"));

            RouteParameters parameters = await routeTask.CreateDefaultParametersAsync();
            parameters.SetStops(stops);
            parameters.ReturnDirections = true;
            parameters.ReturnRoutes = true;

            var result = await routeTask.SolveRouteAsync(parameters);

            if (result?.Routes?.FirstOrDefault() is Route routeResult)
            {
                _routeGraphic.Geometry = routeResult.RouteGeometry;
                Directions = routeResult.DirectionManeuvers.Select(maneuver => maneuver.DirectionText).ToList();
                _currentState = RouteBuilderStatus.NotStarted;
            }
            else
            {
                ResetState();
                throw new Exception("Route not found");
            }
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Handle user taps on the map

The user will tap (or click) locations on the map to define start and end points for the route. The MapView control will accept the user input but the MapViewModel class will contain the logic to handle tap locations and to define stops for solving the route.

Create a function in MapViewModel to handle MapPoint input from the user. Depending on the current RouteBuilderStatus, the point sets the geometry for the start or end location graphic. If the current point defines the end location, a call to FindRoute() solves the route.

MapViewModel.cs
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            if (result?.Routes?.FirstOrDefault() is Route routeResult)
            {
                _routeGraphic.Geometry = routeResult.RouteGeometry;
                Directions = routeResult.DirectionManeuvers.Select(maneuver => maneuver.DirectionText).ToList();
                _currentState = RouteBuilderStatus.NotStarted;
            }
            else
            {
                ResetState();
                throw new Exception("Route not found");
            }

        }

        public async Task HandleTap(MapPoint tappedPoint)
        {
            switch (_currentState)
            {
                case RouteBuilderStatus.NotStarted:
                    ResetState();
                    _startGraphic.Geometry = tappedPoint;
                    _currentState = RouteBuilderStatus.SelectedStart;
                    break;
                case RouteBuilderStatus.SelectedStart:
                    _endGraphic.Geometry = tappedPoint;
                    _currentState = RouteBuilderStatus.SelectedStartAndEnd;
                    await FindRoute();
                    break;
                case RouteBuilderStatus.SelectedStartAndEnd:
                    // Ignore map clicks while routing is in progress
                    break;
            }
        }
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In the Visual Studio > Solution Explorer, double-click MainWindow.xaml.cs to open the file.

Add a handler for the GeoView.GeoViewTapped event. The event will fire when the user taps (or clicks) the MapView. The tapped location will be passed to MapViewModel.HandleTap().

Asynchronous functions should return Task or Task<T>. For event handlers, such as the Button.Click handler, the function must return void to conform to the delegate signature. See the Microsoft documentation regarding Async return types.

MainWindow.xaml.cs
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        public MainWindow()
        {
            InitializeComponent();
        }

        public async void MainMapView_GeoViewTapped(object sender, GeoViewInputEventArgs e)
        {
            try
            {
                var viewmodel = Resources["MapViewModel"] as MapViewModel;
                if (viewmodel != null && e?.Location != null)
                {
                    await viewmodel.HandleTap(e.Location);
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show("Error", ex.Message);
            }
        }
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Bind UI elements to the view model

MapViewModel has properties for graphics overlays (MapViewModel.GraphicsOverlays) and driving directions (MapViewModel.Directions) that must be bound to UI elements to be presented to the user. The GeoView.GeoViewTapped event must also be handled so the view model can accept map locations from the user.

In the Visual Studio > Solution Explorer, double-click MainWindow.xaml to open the file.

Use data binding to bind the GraphicsOverlays property of the MapViewModel to the MapView control. Handle the GeoViewTapped event with the MainMapView_GeoViewTapped function.

Data binding and the Model-View-ViewModel (MVVM) design pattern allow you to separate the logic in your app (the view model) from the presentation layer (the view). Graphics can be added and removed from the graphics overlays in the view model, and those changes appear in the map view through data binding.

MainWindow.xaml
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    <Window.Resources>
        <local:MapViewModel x:Key="MapViewModel" />
    </Window.Resources>
    <Grid>
        <esri:MapView x:Name="MainMapView"
                      Map="{Binding Map, Source={StaticResource MapViewModel}}"
                      GraphicsOverlays="{Binding GraphicsOverlays, Source={StaticResource MapViewModel}}"
                      GeoViewTapped="MainMapView_GeoViewTapped" />
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Add a ListView element and bind its ItemSource to the MapViewModel.Directions property. When a route is successfully solved, the turn-by-turn directions will appear here.

MainWindow.xaml
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        <Border Background="White"
                BorderBrush="Black"
                Margin="10"
                HorizontalAlignment="Right"
                VerticalAlignment="Top"
                Width="300" Height="200">

            <ListView ItemsSource="{Binding Directions, Mode=OneWay, Source={StaticResource MapViewModel}}" />
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Run the app

Click Debug > Start Debugging (or press <F5> on the keyboard) to run the app. If your app uses user authentication, enter your ArcGIS Online credentials when prompted.

Clicks on the map should alternate between creating an origin and destination point. When both points are defined, the route task uses the route service to find the best route and provide turn-by-turn directions.

Alternatively, you can download the tutorial solution, as follows.

Option 2: Download the solution

Click the Download solution link in the right-hand panel of the page.
Unzip the file to a location on your machine.
Open the .sln file in Visual Studio.

Since the downloaded solution does not contain authentication credentials, you must add the developer credentials that you created in the Set up authentication section.

Set developer credentials in the solution

To allow your app users to access ArcGIS location services, use the developer credentials that you created in the Set up authentication step to authenticate requests for resources.

In Visual Studio, in the Solution Explorer, click App.xaml.cs to open the file.

Set the ArcGISEnvironment.ApiKey property with your API key access token.

App.xaml.cs
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        protected override void OnStartup(StartupEventArgs e)
        {
            base.OnStartup(e);

            // Set the access token for ArcGIS Maps SDK for .NET.
            Esri.ArcGISRuntime.ArcGISRuntimeEnvironment.ApiKey = "YOUR_ACCESS_TOKEN";

            // Call a function to set up the AuthenticationManager for OAuth.
            UserAuth.ArcGISLoginPrompt.SetChallengeHandler();

        }

Remove the code that sets up user authentication.

App.xaml.cs
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        protected override void OnStartup(StartupEventArgs e)
        {
            base.OnStartup(e);

            // Set the access token for ArcGIS Maps SDK for .NET.
            Esri.ArcGISRuntime.ArcGISRuntimeEnvironment.ApiKey = "YOUR_ACCESS_TOKEN";

            // Call a function to set up the AuthenticationManager for OAuth.
            UserAuth.ArcGISLoginPrompt.SetChallengeHandler();

        }

Best Practice: The access token is stored directly in the code as a convenience for this tutorial. Do not store credentials directly in source code in a production environment.

From the Visual Studio Solution explorer window, open the ArcGISLoginPrompt.cs file.

Set your values for the client ID (OAuthClientID) and the redirect URL (OAuthRedirectUrl). These are the user authentication settings you created in the Set up authentication step.

ArcGISLoginPrompt.cs
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    internal static class ArcGISLoginPrompt
    {
        private const string ArcGISOnlineUrl = "https://www.arcgis.com/sharing/rest";
        // Specify the Client ID and Redirect URL to use with OAuth authentication.
        // See the instructions here for creating OAuth app settings:
        // https://developers.arcgis.com/documentation/security-and-authentication/user-authentication/tutorials/create-oauth-credentials-user-auth/

        private const string AppClientId = "YOUR_CLIENT_ID";
        private const string OAuthRedirectUrl = "YOUR_REDIRECT_URL";

In Visual Studio, in the Solution Explorer, click App.xaml.cs to open the file.

Remove the line of code that sets an API key access token.

App.xaml.cs
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        protected override void OnStartup(StartupEventArgs e)
        {
            base.OnStartup(e);

            // Set the access token for ArcGIS Maps SDK for .NET.
            Esri.ArcGISRuntime.ArcGISRuntimeEnvironment.ApiKey = "YOUR_ACCESS_TOKEN";

            // Call a function to set up the AuthenticationManager for OAuth.
            UserAuth.ArcGISLoginPrompt.SetChallengeHandler();

        }

Best Practice: The OAuth credentials are stored directly in the code as a convenience for this tutorial. Do not store credentials directly in source code in a production environment.

Run the solution

Click Debug > Start Debugging (or press <F5> on the keyboard) to run the app. If your app uses user authentication, enter your ArcGIS Online credentials when prompted.

What's next?

To explore more API features and ArcGIS location services, try the following tutorial: