I use the sample project too test my implementation with the XamDataChart. 

Unfortunately the Legend appears, but there no Items shown. 

<UserControl
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:local="clr-namespace:Module1.Views"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             xmlns:prism="http://prismlibrary.com/"
             xmlns:ig="http://schemas.infragistics.com/xaml"
             xmlns:sapmleData="clr-namespace:HAWO.SapmleData;assembly=HAWO.SapmleData"
             xmlns:viewModels="clr-namespace:Module1.ViewModels"
             x:Class="Module1.Views.ViewA"
             mc:Ignorable="d" 
             d:DesignHeight="300" d:DesignWidth="300"
              
             prism:ViewModelLocator.AutoWireViewModel="True" >
    <Grid>
        <ig:XamDataChart x:Name="Chart" Legend="{Binding ElementName=ItemLegend}">
            <ig:XamDataChart.Resources>
                <sapmleData:EnergyDataSource x:Key="data" />
            </ig:XamDataChart.Resources>
            <ig:XamDataChart.Axes>
                <ig:NumericYAxis x:Name="YAxis"  />
                <ig:CategoryXAxis x:Name="XAxis" ItemsSource="{StaticResource data}"
                                  Label="{}{Country}"
                                  />
            </ig:XamDataChart.Axes>
            <ig:XamDataChart.Series>
                <ig:LineSeries ItemsSource="{StaticResource data}" ValueMemberPath="Coal" Title="Coal"
                               XAxis="{Binding ElementName=XAxis}"
                               YAxis="{Binding ElementName=YAxis}">
                </ig:LineSeries>
                <ig:LineSeries ItemsSource="{StaticResource data}" ValueMemberPath="Hydro" Title="Hydro"
                               XAxis="{Binding ElementName=XAxis}"
                               YAxis="{Binding ElementName=YAxis}">
                </ig:LineSeries>
                <ig:LineSeries ItemsSource="{StaticResource data}" ValueMemberPath="Nuclear" Title="Nuclear"
                               XAxis="{Binding ElementName=XAxis}"
                               YAxis="{Binding ElementName=YAxis}">
                </ig:LineSeries>
                <ig:LineSeries ItemsSource="{StaticResource data}" ValueMemberPath="Gas" Title="Gas"
                               XAxis="{Binding ElementName=XAxis}"
                               YAxis="{Binding ElementName=YAxis}">
                </ig:LineSeries>
                <ig:LineSeries ItemsSource="{StaticResource data}" ValueMemberPath="Oil"  Title="Oil"
                               XAxis="{Binding ElementName=XAxis}"
                               YAxis="{Binding ElementName=YAxis}">
                </ig:LineSeries>
            </ig:XamDataChart.Series>
        </ig:XamDataChart >
        <ig:ItemLegend x:Name="ItemLegend" Content="content" Margin="0,10,40,0" Height="64"/>
    </Grid>
</UserControl>

I guess this should work without code behind. 

Best Nic,