HeatmapDataSourceAdapter Class

<Window
        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" 
        xmlns:local="clr-namespace:Heatmap" 
        xmlns:dxm="http://schemas.devexpress.com/winfx/2008/xaml/map" 
        x:Class="Heatmap.MainWindow" 
        mc:Ignorable="d" 
        Title="MainWindow" Height="450" Width="800">
    <Window.DataContext>
        <local:EarthquakesData/>
    </Window.DataContext>
    <Grid>
        <dxm:MapControl ZoomLevel="2">
            <dxm:ImageLayer>
                <dxm:BingMapDataProvider BingKey="Your Bing Maps key here."/>
            </dxm:ImageLayer>
            <!-- The heatmap layer configuration -->
            <dxm:ImageLayer Name="heatmapLayer" Opacity="0.75">
                <dxm:HeatmapProvider>
                    <dxm:HeatmapProvider.Colorizer>
                        <dxm:ChoroplethColorizer RangeStops="0.1, 0.2, 0.7, 1.0" 
                                                 ApproximateColors="True">
                            <dxm:ChoroplethColorizer.Colors>
                                <Color A="50"  R="128"  G="255"  B="0"/>
                                <Color A="255" R="255"  G="255"  B="0"/>
                                <Color A="255" R="234"  G="72"   B="58"/>
                                <Color A="255" R="162"  G="36"   B="25"/>
                            </dxm:ChoroplethColorizer.Colors>
                        </dxm:ChoroplethColorizer>
                    </dxm:HeatmapProvider.Colorizer>
                    <dxm:HeatmapProvider.PointSource>
                        <dxm:HeatmapDataSourceAdapter DataSource="{Binding Path=DataItems}">
                            <dxm:HeatmapDataSourceAdapter.Mappings>
                                <dxm:HeatmapPointMappingInfo XCoordinate="Longitude" 
                                                             YCoordinate="Latitude"/>
                            </dxm:HeatmapDataSourceAdapter.Mappings>
                        </dxm:HeatmapDataSourceAdapter>
                    </dxm:HeatmapProvider.PointSource>
                    <dxm:HeatmapProvider.Algorithm>
                        <dxm:HeatmapDensityBasedAlgorithm PointRadius="10"/>
                    </dxm:HeatmapProvider.Algorithm>
                </dxm:HeatmapProvider>
            </dxm:ImageLayer>
            <!--...-->
        </dxm:MapControl>
    </Grid>
</Window>

using System;
using System.Collections.Generic;
using System.IO;
using System.Windows;
using System.Xml.Serialization;
namespace Heatmap {
    public partial class MainWindow : Window {
        public MainWindow() {
            InitializeComponent();
        }
    }
    public class EarthquakeViewModel {
        [XmlElement("glat")]
        public double Latitude { get; set; }
        [XmlElement("glon")]
        public double Longitude { get; set; }
    }
    [XmlRoot("Data")]
    public class EarthquakesData {
        static EarthquakesData instance;
        public static List<EarthquakeViewModel> DataItems {
            get { return Instance.Items; }
        }
        public static EarthquakesData Instance {
            get { return instance ?? (instance = CreateInstance()); }
        }
        static EarthquakesData CreateInstance() {
            XmlSerializer serializer = new XmlSerializer(typeof(EarthquakesData));
            Stream documentStream = LoadStreamFromResources("/Data/Earthquakes.xml");
            return (EarthquakesData)serializer.Deserialize(documentStream);
        }
        [XmlElement("Row")]
        public List<EarthquakeViewModel> Items { get; set; }
        public static Stream LoadStreamFromResources(string fileName) {
            try {
                Uri uri = new Uri(fileName, UriKind.RelativeOrAbsolute);
                return Application.GetResourceStream(uri).Stream;
            }
            catch {
                return null;
            }
        }
    }
}

Imports System
Imports System.Collections.Generic
Imports System.IO
Imports System.Windows
Imports System.Xml.Serialization
Namespace Heatmap
    Public Partial Class MainWindow
        Inherits Window
        Public Sub New()
            InitializeComponent()
        End Sub 
    End Class 
    Public Class EarthquakeViewModel
        <XmlElement("glat")>
        Public Property Latitude As Double 
        <XmlElement("glon")>
        Public Property Longitude As Double 
    End Class 
    <XmlRoot("Data")>
    Public Class EarthquakesData
        Shared instance As EarthquakesData
        Public Shared ReadOnly Property DataItems As List(Of EarthquakeViewModel)
            Get 
                Return Instance.Items
            End Get 
        End Property 
        Public Shared ReadOnly Property Instance As EarthquakesData
            Get 
                Return If(instance, (CSharpImpl.__Assign(instance, CreateInstance())))
            End Get 
        End Property 
        Private Shared Function CreateInstance() As EarthquakesData
            Dim serializer As XmlSerializer = New XmlSerializer(GetType(EarthquakesData))
            Dim documentStream As Stream = LoadStreamFromResources("/Data/Earthquakes.xml")
            Return CType(serializer.Deserialize(documentStream), EarthquakesData)
        End Function 
        <XmlElement("Row")>
        Public Property Items As List(Of EarthquakeViewModel)
        Public Shared Function LoadStreamFromResources(ByVal fileName As String) As Stream
            Try 
                Dim uri As Uri = New Uri(fileName, UriKind.RelativeOrAbsolute)
                Return Application.GetResourceStream(uri).Stream
            Catch 
                Return Nothing 
            End Try 
        End Function 
        Private Class CSharpImpl
            Shared Function __Assign(Of T)(ByRef target As T, value As T) As T
                target = value
                Return value
            End Function 
        End Class 
    End Class 
End Namespace