Create and save map

// 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 ArcGIS.Helpers;
using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Portal;
using Esri.ArcGISRuntime.UI;
using System;
using System.Collections.Generic;
using System.IO;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;

namespace ArcGIS.WPF.Samples.AuthorMap
{
    [ArcGIS.Samples.Shared.Attributes.Sample(
        name: "Create and save map",
        category: "Map",
        description: "Create and save a map as an ArcGIS `PortalItem` (i.e. web map).",
        instructions: "1. Select the basemap and layers you'd like to add to your map.",
        tags: new[] { "ArcGIS Online", "OAuth", "portal", "publish", "share", "web map" })]
    [ArcGIS.Samples.Shared.Attributes.ClassFile("Helpers\\ArcGISLoginPrompt.cs")]
    public partial class AuthorMap
    {
        // String array to store names of the available basemaps
        private readonly string[] _basemapNames =
        {
            "Light Gray",
            "Topographic",
            "Streets",
            "Imagery",
            "Ocean"
        };

        // Dictionary of operational layer names and URLs
        private Dictionary<string, string> _operationalLayerUrls = new Dictionary<string, string>
        {
            {"World Elevations", "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Elevation/WorldElevations/MapServer"},
            {"World Cities", "https://sampleserver6.arcgisonline.com/arcgis/rest/services/SampleWorldCities/MapServer/" },
            {"US Census Data", "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer"}
        };

        public AuthorMap()
        {
            this.Loaded += (s, e) => { _ = Initialize(); };
            InitializeComponent();
        }

        private async Task Initialize()
        {
            ArcGISLoginPrompt.SetChallengeHandler();

            bool loggedIn = await ArcGISLoginPrompt.EnsureAGOLCredentialAsync();

            // Show a plain gray map in the map view.
            if (loggedIn)
            {
                MyMapView.Map = new Map(BasemapStyle.ArcGISLightGray);
            }
            else MyMapView.Map = new Map();

            // Fill the basemap combo box with basemap names
            BasemapListBox.ItemsSource = _basemapNames;

            // Add a listener for changes in the selected basemap.
            BasemapListBox.SelectionChanged += BasemapSelectionChanged;

            // Fill the operational layers list box with layer names
            OperationalLayerListBox.ItemsSource = _operationalLayerUrls;

            // Update the extent labels whenever the view point (extent) changes
            MyMapView.ViewpointChanged += (s, evt) => UpdateViewExtentLabels();
        }

        #region UI event handlers

        private void BasemapSelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            // Call a function to set the basemap to the one selected
            ApplyBasemap(e.AddedItems[0].ToString());
        }

        private void OperationalLayerSelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            // Call a function to add the chosen layers to the map
            AddOperationalLayers();
        }

        private void NewMapClicked(object sender, RoutedEventArgs e)
        {
            // Create a new map (will not have an associated PortalItem)
            MyMapView.Map = new Map(BasemapStyle.ArcGISLightGray);
            MyMapView.Map.Basemap.LoadAsync();

            // Reset UI to be consistent with map
            BasemapListBox.SelectedIndex = 0;
            OperationalLayerListBox.SelectedIndex = -1;
        }

        private async void SaveMapClicked(object sender, RoutedEventArgs e)
        {
            try
            {
                // Show the progress bar so the user knows work is happening
                SaveProgressBar.Visibility = Visibility.Visible;

                // Get the current map
                Map myMap = MyMapView.Map;

                // Load the current map before saving to portal.
                await myMap.LoadAsync();

                // Apply the current extent as the map's initial extent
                myMap.InitialViewpoint = MyMapView.GetCurrentViewpoint(ViewpointType.BoundingGeometry);

                // Get the current map view for the item thumbnail
                RuntimeImage thumbnailImg = await MyMapView.ExportImageAsync();

                // See if the map has already been saved (has an associated portal item)
                if (myMap.Item == null)
                {
                    // Get information for the new portal item
                    string title = TitleTextBox.Text;
                    string description = DescriptionTextBox.Text;
                    string[] tags = TagsTextBox.Text.Split(',');

                    // Make sure all required info was entered
                    if (string.IsNullOrEmpty(title) || string.IsNullOrEmpty(description) || tags.Length == 0)
                    {
                        throw new Exception("Please enter a title, description, and some tags to describe the map.");
                    }

                    // Call a function to save the map as a new portal item
                    await SaveNewMapAsync(MyMapView.Map, title, description, tags, thumbnailImg);

                    // Report a successful save
                    MessageBox.Show("Saved '" + title + "' to ArcGIS Online!", "Map Saved");
                }
                else
                {
                    // This is not the initial save, call SaveAsync to save changes to the existing portal item
                    await myMap.SaveAsync();

                    // Get the file stream from the new thumbnail image
                    Stream imageStream = await thumbnailImg.GetEncodedBufferAsync();

                    // Update the item thumbnail
                    ((PortalItem)myMap.Item).SetThumbnail(imageStream);
                    await myMap.SaveAsync();

                    // Report update was successful
                    MessageBox.Show("Saved changes to '" + myMap.Item.Title + "'", "Updates Saved");
                }
            }
            catch (Exception ex)
            {
                // Report error message
                MessageBox.Show("Error saving map to ArcGIS Online: " + ex.Message);
            }
            finally
            {
                // Hide the progress bar
                SaveProgressBar.Visibility = Visibility.Hidden;
            }
        }

        #endregion UI event handlers

        private void ApplyBasemap(string basemapName)
        {
            // Set the basemap for the map according to the user's choice in the list box.
            switch (basemapName)
            {
                case "Light Gray":
                    MyMapView.Map.Basemap = new Basemap(BasemapStyle.ArcGISLightGray);
                    break;

                case "Topographic":
                    MyMapView.Map.Basemap = new Basemap(BasemapStyle.ArcGISTopographic);
                    break;

                case "Streets":
                    MyMapView.Map.Basemap = new Basemap(BasemapStyle.ArcGISStreets);
                    break;

                case "Imagery":
                    MyMapView.Map.Basemap = new Basemap(BasemapStyle.ArcGISImagery);
                    break;

                case "Ocean":
                    MyMapView.Map.Basemap = new Basemap(BasemapStyle.ArcGISOceans);
                    break;
            }

            MyMapView.Map.Basemap.LoadAsync();
        }

        private void AddOperationalLayers()
        {
            // Clear all operational layers from the map
            Map myMap = MyMapView.Map;
            myMap.OperationalLayers.Clear();

            // Loop through the selected items in the operational layers list box
            foreach (KeyValuePair<string, string> item in OperationalLayerListBox.SelectedItems)
            {
                // Get the service uri for each selected item
                KeyValuePair<string, string> layerInfo = item;
                Uri layerUri = new Uri(layerInfo.Value);

                // Create a new map image layer, set it 50% opaque, and add it to the map
                ArcGISMapImageLayer layer = new ArcGISMapImageLayer(layerUri)
                {
                    Opacity = 0.5
                };
                myMap.OperationalLayers.Add(layer);
            }
        }

        private async Task SaveNewMapAsync(Map myMap, string title, string description, string[] tags, RuntimeImage thumb)
        {
            await ArcGISLoginPrompt.EnsureAGOLCredentialAsync();

            // Get the ArcGIS Online portal (will use credential from login above)
            ArcGISPortal agsOnline = await ArcGISPortal.CreateAsync();

            // Save the current state of the map as a portal item in the user's default folder
            await myMap.SaveAsAsync(agsOnline, null, title, description, tags, thumb);
        }

        private void UpdateViewExtentLabels()
        {
            // Get the current view point for the map view
            Viewpoint currentViewpoint = MyMapView.GetCurrentViewpoint(ViewpointType.BoundingGeometry);
            if (currentViewpoint == null) { return; }

            // Get the current map extent (envelope) from the view point
            Envelope currentExtent = currentViewpoint.TargetGeometry as Envelope;

            // Project the current extent to geographic coordinates (longitude / latitude)
            Envelope currentGeoExtent = (Envelope)currentExtent.Project(SpatialReferences.Wgs84);

            // Fill the app text boxes with min / max longitude (x) and latitude (y) to four decimal places
            XMinTextBox.Text = currentGeoExtent.XMin.ToString("0.####");
            YMinTextBox.Text = currentGeoExtent.YMin.ToString("0.####");
            XMaxTextBox.Text = currentGeoExtent.XMax.ToString("0.####");
            YMaxTextBox.Text = currentGeoExtent.YMax.ToString("0.####");
        }
    }
}

<UserControl x:Class="ArcGIS.WPF.Samples.AuthorMap.AuthorMap"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:esri="http://schemas.esri.com/arcgis/runtime/2013">
    <UserControl.Resources>
        <Style TargetType="ListBox" BasedOn="{StaticResource CalciteListBoxStyle}">
            <Setter Property="Margin" Value="10" />
        </Style>
        <Style TargetType="TextBlock">
            <Setter Property="Margin" Value="0,5,5,0" />
            <Setter Property="VerticalAlignment" Value="Top" />
        </Style>
        <Style TargetType="TextBox">
            <Setter Property="Margin" Value="0,5,0,0" />
            <Setter Property="Padding" Value="2.5" />
        </Style>
    </UserControl.Resources>
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="300" />
            <ColumnDefinition />
        </Grid.ColumnDefinitions>
        <ScrollViewer>
            <Grid Grid.Column="0">
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto" />
                <RowDefinition Height="Auto" />
                <RowDefinition Height="Auto" />
                <RowDefinition Height="Auto" />
                <RowDefinition Height="Auto" />
            </Grid.RowDefinitions>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="Auto" />
                <ColumnDefinition />
            </Grid.ColumnDefinitions>
            <TextBlock Grid.Row="0"
                       Margin="10,10,0,0"
                       HorizontalAlignment="Right"
                       Text="Select a basemap:" />
            <ListBox x:Name="BasemapListBox"
                     Grid.Row="0"
                     Grid.Column="1"
                     HorizontalAlignment="Stretch" />
            <TextBlock Grid.Row="1"
                       Grid.Column="0"
                       Margin="10,10,0,0"
                       HorizontalAlignment="Right"
                       Text="Choose layers:" />
            <ListBox x:Name="OperationalLayerListBox"
                     Grid.Row="1"
                     Grid.Column="1"
                     HorizontalAlignment="Stretch"
                     SelectionChanged="OperationalLayerSelectionChanged"
                     SelectionMode="Multiple">
                <ListBox.ItemTemplate>
                    <DataTemplate>
                        <TextBlock Text="{Binding Key}" />
                    </DataTemplate>
                </ListBox.ItemTemplate>
            </ListBox>
            <TextBlock Grid.Row="2"
                       Grid.Column="0"
                       Margin="10,15,0,0"
                       HorizontalAlignment="Right"
                       Text="Initial Extent:" />
            <Grid Grid.Row="2"
                  Grid.Column="1"
                  Margin="10">
                <Grid.RowDefinitions>
                    <RowDefinition Height="Auto" />
                    <RowDefinition Height="Auto" />
                    <RowDefinition Height="Auto" />
                    <RowDefinition Height="Auto" />
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition Width="*" />
                </Grid.ColumnDefinitions>
                <TextBlock Grid.Row="0"
                           Grid.Column="0"
                           VerticalAlignment="Center"
                           Text="X Min:" />
                <TextBox x:Name="XMinTextBox"
                         Grid.Row="0"
                         Grid.Column="1"
                         HorizontalAlignment="Stretch"
                         IsReadOnly="True" />
                <TextBlock Grid.Row="1"
                           Grid.Column="0"
                           VerticalAlignment="Center"
                           Text="Y Min:" />
                <TextBox x:Name="YMinTextBox"
                         Grid.Row="1"
                         Grid.Column="1"
                         IsReadOnly="True"
                         Text="" />
                <TextBlock Grid.Row="2"
                           Grid.Column="0"
                           VerticalAlignment="Center"
                           Text="X Max:" />
                <TextBox x:Name="XMaxTextBox"
                         Grid.Row="2"
                         Grid.Column="1"
                         IsReadOnly="True"
                         Text="" />
                <TextBlock Grid.Row="3"
                           Grid.Column="0"
                           VerticalAlignment="Center"
                           Text="Y Max:" />
                <TextBox x:Name="YMaxTextBox"
                         Grid.Row="3"
                         Grid.Column="1"
                         IsReadOnly="True"
                         Text="" />
            </Grid>
            <Button Grid.Row="3"
                    Grid.Column="0"
                    Grid.ColumnSpan="2"
                    Margin="10"
                    Padding="5"
                    HorizontalAlignment="Stretch"
                    VerticalAlignment="Top"
                    Click="NewMapClicked"
                    Content="New Map" />
            <Grid x:Name="SaveMapGrid"
                  Grid.Row="4"
                  Grid.Column="0"
                  Grid.ColumnSpan="2"
                  Margin="10"
                  Visibility="Visible">
                <Grid.RowDefinitions>
                    <RowDefinition Height="Auto" />
                    <RowDefinition Height="Auto" />
                    <RowDefinition Height="Auto" />
                    <RowDefinition Height="Auto" />
                    <RowDefinition Height="Auto" />
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition Width="*" />
                </Grid.ColumnDefinitions>
                <TextBlock HorizontalAlignment="Right"
                           VerticalAlignment="Center"
                           Text="Title:" />
                <TextBox x:Name="TitleTextBox"
                         Grid.Row="0"
                         Grid.Column="1"
                         HorizontalAlignment="Stretch"
                         Text="My Map" />
                <TextBlock Grid.Row="1"
                           Grid.Column="0"
                           HorizontalAlignment="Right"
                           Text="Description:" />
                <TextBox x:Name="DescriptionTextBox"
                         Grid.Row="1"
                         Grid.Column="1"
                         HorizontalAlignment="Stretch"
                         Text="Authored and saved using ArcGIS Maps SDK for .NET."
                         TextWrapping="Wrap" />
                <TextBlock Grid.Row="2"
                           Grid.Column="0"
                           HorizontalAlignment="Right"
                           VerticalAlignment="Center"
                           Text="Tags:" />
                <TextBox x:Name="TagsTextBox"
                         Grid.Row="2"
                         Grid.Column="1"
                         HorizontalAlignment="Stretch"
                         Text="ArcGIS, Sample" />
                <Button Grid.Row="3"
                        Grid.Column="0"
                        Grid.ColumnSpan="2"
                        Margin="0,10,0,0"
                        Padding="5"
                        HorizontalAlignment="Stretch"
                        Click="SaveMapClicked"
                        Content="Save Map to Portal"
                        IsEnabled="{Binding ElementName=MyMapView}" />
                <ProgressBar x:Name="SaveProgressBar"
                             Grid.Row="4"
                             Grid.Column="0"
                             Grid.ColumnSpan="2"
                             Height="15"
                             Margin="10,0,10,0"
                             HorizontalAlignment="Stretch"
                             IsIndeterminate="True"
                             Visibility="Hidden" />
            </Grid>
            </Grid>
    </ScrollViewer>
    <esri:MapView x:Name="MyMapView" Grid.Column="1" />
    </Grid>
</UserControl>

// 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 Microsoft.Web.WebView2.Core;
using Microsoft.Web.WebView2.Wpf;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Threading;

namespace ArcGIS.Helpers
{
    internal static class ArcGISLoginPrompt
    {
        private const string ArcGISOnlineUrl = "https://www.arcgis.com/sharing/rest";

        // - The Client ID for an app registered with the server (the ID below is for a public app created by the ArcGIS Maps SDK for Native Apps team).
        private const string AppClientId = "lgAdHkYZYlwwfAhC";

        // - An optional client secret for the app (only needed for the OAuthClientCredentials authorization type).
        private const string ClientSecret = "";

        // - A URL for redirecting after a successful authorization (this must be a URL configured with the app).
        private const string OAuthRedirectUrl = "my-ags-app://auth";

        public static async Task<bool> EnsureAGOLCredentialAsync()
        {
            Credential currentCredential = AuthenticationManager.Current.FindCredential(new Uri(ArcGISOnlineUrl), AuthenticationType.Token);
            if (currentCredential != null)
            {
                return true; // already logged in
            }

            try
            {
                var userConfig = new OAuthUserConfiguration(new Uri(ArcGISOnlineUrl), AppClientId, new Uri(OAuthRedirectUrl));
                Credential cred = await OAuthUserCredential.CreateAsync(userConfig);
                AuthenticationManager.Current.AddCredential(cred);
            }
            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 false;
        }

        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)
            {
                // Initialize a WebView2 control to display the authorize page.
                WebView2 webBrowser = new WebView2() { MinWidth = 500, MinHeight = 500 };

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

                // Display the web browser in a new window.
                _authWindow = new Window
                {
                    Content = webBrowser,
                    SizeToContent = SizeToContent.WidthAndHeight,
                    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 window loaded event as the WebView2 control can only be initialized after it is visible in the UI
                _authWindow.Loaded += async (s, e) =>
                {
                    await webBrowser.EnsureCoreWebView2Async();
                    webBrowser.CoreWebView2.Navigate(authorizeUri);
                };

                // Handle the window closed event
                _authWindow.Closed += OnWindowClosed;

                // 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
            private void WebBrowserOnNavigationStarting(object sender, CoreWebView2NavigationStartingEventArgs e)
            {
                // Check for a response to the callback url.
                const string portalApprovalMarker = "/oauth2/approval";

                Uri uri = new Uri(e.Uri);

                // If no browser, uri, or an empty url, return.
                if (sender == 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
    }
}