FeatureServiceWithPopups

<UserControl xmlns:esri="http://schemas.esri.com/arcgis/client/2009"  x:Class="FeatureServiceWithPopups.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">

    <Grid x:Name="LayoutRoot" Background="White">
        <esri:Map x:Name="MyMap" />

        <esri:InfoWindow x:Name="MyInfoWindow"
                         Padding="2"
                         CornerRadius="10"                        
                         Map="{Binding ElementName=MyMap}" >
            <esri:InfoWindow.Background>
                <LinearGradientBrush EndPoint="1.038,1.136" StartPoint="0.015,0.188">
                    <GradientStop Color="#FFD1DFF2"/>
                    <GradientStop Color="#FF666666" Offset="0.946"/>
                </LinearGradientBrush>
            </esri:InfoWindow.Background>
        </esri:InfoWindow>

        <Grid HorizontalAlignment="Right" VerticalAlignment="Top" Margin="0,15,15,0" >
            <Rectangle Fill="#77919191" Stroke="Gray"  RadiusX="10" RadiusY="10" Margin="0,0,0,5" >
                <Rectangle.Effect>
                    <DropShadowEffect/>
                </Rectangle.Effect>
            </Rectangle>
            <Rectangle Fill="#FFFFFFFF" Stroke="DarkGray" RadiusX="5" RadiusY="5" Margin="10,10,10,15" />
            <StackPanel Orientation="Vertical" Margin="25,20,25,25">
                <TextBlock Text="Display Attributes In:" Foreground="Black" FontWeight="Bold" FontSize="12" Margin="3" />
                <RadioButton GroupName="MyRadioButtons" Checked="MapTipRadioButton_Checked" IsChecked="True" Content="Map Tip" Margin="2" />
                <RadioButton GroupName="MyRadioButtons" Checked="InfoWindowRadioButton_Unchecked" Content="Info Window" Margin="2"/>
            </StackPanel>
        </Grid>

    </Grid>
</UserControl>

using ESRI.ArcGIS.Client;
using ESRI.ArcGIS.Client.Geometry;
using ESRI.ArcGIS.Client.WebMap;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace FeatureServiceWithPopups
{
    public partial class MainPage : UserControl
    {
        Dictionary<string, FrameworkElement> mapTipsElements = new Dictionary<string, FrameworkElement>();
        MapPoint lastPoint = null;


        public MainPage()
        {
            InitializeComponent();
            Document webMap = new Document();
            webMap.GetMapCompleted += webMap_GetMapCompleted;

            webMap.GetMapAsync("921e9016d2a5423da8bd08eb306e4e0e");

        }
        void webMap_GetMapCompleted(object sender, GetMapCompletedEventArgs e)
        {
            if (e.Error == null)
            {
                MyMap.Extent = e.Map.Extent;
                int i = 0;

                LayerCollection layerCollection = new LayerCollection();
                foreach (Layer layer in e.Map.Layers)
                {
                    layer.ID = i.ToString();
                    if (layer is FeatureLayer)
                    {
                        mapTipsElements.Add(layer.ID, (layer as FeatureLayer).MapTip);
                    }
                    layerCollection.Add(layer);
                    i++;
                }

                e.Map.Layers.Clear();
                MyMap.Layers = layerCollection;
            }
        }
        private void MapTipRadioButton_Checked(object sender, RoutedEventArgs e)
        {
            if (MyMap != null)
            {
                MyInfoWindow.IsOpen = false;
                foreach (Layer layer in MyMap.Layers)
                {
                    if (layer is FeatureLayer)
                        (layer as FeatureLayer).MouseLeftButtonUp -= WebMapFeatureServicePopups_MouseLeftButtonUp;
                    if (mapTipsElements.ContainsKey(layer.ID))
                        (layer as FeatureLayer).MapTip = mapTipsElements[layer.ID];
                }
            }
        }

        private void InfoWindowRadioButton_Unchecked(object sender, RoutedEventArgs e)
        {
            foreach (Layer layer in MyMap.Layers)
                if (layer is FeatureLayer)
                {
                    (layer as FeatureLayer).MapTip = null;
                    (layer as FeatureLayer).MouseLeftButtonUp += WebMapFeatureServicePopups_MouseLeftButtonUp;
                }
        }

        void WebMapFeatureServicePopups_MouseLeftButtonUp(object sender, GraphicMouseButtonEventArgs e)
        {
            FeatureLayer flayer = sender as FeatureLayer;
            MapPoint clickPoint = MyMap.ScreenToMap(e.GetPosition(MyMap));

            if (clickPoint != lastPoint)
            {
                if (flayer.GetValue(Document.PopupTemplateProperty) != null)
                {
                    DataTemplate dt = flayer.GetValue(Document.PopupTemplateProperty) as DataTemplate;

                    MyInfoWindow.Anchor = clickPoint;
                    MyInfoWindow.ContentTemplate = dt;
                    MyInfoWindow.Content = e.Graphic.Attributes;
                    MyInfoWindow.IsOpen = true;
                    lastPoint = clickPoint;
                }
            }

        }
    }
}