<Telerik:RadChart ItemsSource="{Binding Path=SeriesCollection,Mode=TwoWay}" x:Name="chartcontentseries" >

<telerik:RadChart.DefaultSeriesDefinition>

<telerik:SplineSeriesDefinition></telerik:SplineSeriesDefinition>

</telerik:RadChart.DefaultSeriesDefinition>

<telerik:RadChart.SeriesMappings>

<telerik:SeriesMapping CollectionIndex="0" LegendLabel="{Binding Path=CollectionName}">

<telerik:ItemMapping FieldName="Percentage" DataPointMember="YValue"></telerik:ItemMapping>

</telerik:SeriesMapping>

</telerik:RadChart.SeriesMappings>

</telerik:RadChart>

 public class Player
    {
        public string Name
        {
            get;
            set;
        }
 
        public Position Position
        {
        get;
        set;
        }
 
        public Player(string name, Position pos)
        {
            Name = name;
            Position = pos;
        }
    
    }

 public enum Position
    {
        [Description("China")]
        GB,
        [Description("Unite Kingdom")]
        UK,
        [Description("Unite States")]
        US
    }

public class ViewModel
    {
        private List<Player> allPlayers;
        public ObservableCollection<Player> AllPlayers
        {
            get
            {
                if (this.allPlayers == null)
                {
                    this.allPlayers = new List<Player>();
                    this.allPlayers.Add(new Player("Haibng", Position.GB));
                    this.allPlayers.Add(new Player("WHS", Position.UK));
                    this.allPlayers.Add(new Player("NY", Position.US));
 
                }
                return new ObservableCollection<Player>(this.allPlayers);
            }
        }
 
        public IEnumerable<Telerik.Windows.Data.EnumMemberViewModel> Positions
        {
            get
            {
                return Telerik.Windows.Data.EnumDataSource.FromType<Position>();
            }
        }
    }

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525"
        xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
        >    
    <StackPanel>    
        <Button Content="Show Combo in RadWindow" Click="Button_Click" Width="180" Height="30" Margin="10,10,10,10"/>
        <Button Content="Show Combo in Comm Window" Click="Button2_Click" Width="180" Height="30" Margin="10,10,10,10"/>
        <telerik:RadGridView x:Name="radGridView" AutoGenerateColumns="False">
            <telerik:RadGridView.Columns>
                <telerik:GridViewDataColumn Header="Name"  DataMemberBinding="{Binding Name}" TextAlignment="Left" Width="160"/>
                <telerik:GridViewComboBoxColumn  Header="Position"  DataMemberBinding="{Binding Position}" Width="*" />
            </telerik:RadGridView.Columns> 
        </telerik:RadGridView>
    </StackPanel> 
</Window>

public partial class MainWindow : Window
    {
        
        public MainWindow()
        {
            InitializeComponent();
          
 
            ViewModel vm = new ViewModel();
            this.radGridView.ItemsSource = vm.AllPlayers;
 
            GridViewComboBoxColumn combo = (GridViewComboBoxColumn)this.radGridView.Columns[1];
            combo.ItemsSource = vm.Positions;
        }
 
        private void Button_Click(object sender, RoutedEventArgs e)
        {
            RadWin u = new RadWin();
            u.Owner = this;
            u.ShowDialog();
        }        
 
        private void Button2_Click(object sender, RoutedEventArgs e)
        {
            MyWin w = new MyWin();
            w.Owner = this;
            w.ShowInTaskbar = false;
            w.ShowDialog();
        }
    }

<telerik:RadWindow x:Class="WpfApplication1.RadWin"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d" 
             xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
             d:DesignHeight="300" d:DesignWidth="300">
    <Grid>
        <telerik:RadGridView x:Name="radGridView" AutoGenerateColumns="False">
            <telerik:RadGridView.Columns>
                
                <telerik:GridViewDataColumn Header="Name"  DataMemberBinding="{Binding Name}" TextAlignment="Left" Width="160"/>
                <telerik:GridViewComboBoxColumn  Header="Position"  DataMemberBinding="{Binding Position}" Width="*" />
            </telerik:RadGridView.Columns>
 
        </telerik:RadGridView>
        <telerik:RadToolBar>
            <telerik:RadComboBox Name="graphModes" Width="250" Height="22" Margin="3">
                <ComboBoxItem>One</ComboBoxItem>
                <ComboBoxItem>Two</ComboBoxItem>
                <ComboBoxItem>Three</ComboBoxItem>
            </telerik:RadComboBox>
        </telerik:RadToolBar>
    </Grid>
</telerik:RadWindow>

 public partial class RadWin : RadWindow
    {
        public RadWin()
        {
            InitializeComponent();
            this.Width = 400;
            this.Height = 450;
            this.WindowStartupLocation = System.Windows.WindowStartupLocation.CenterOwner;
 
            ViewModel vm = new ViewModel();
            this.radGridView.ItemsSource = vm.AllPlayers;
            
            GridViewComboBoxColumn combo = (GridViewComboBoxColumn)this.radGridView.Columns[1];
            combo.ItemsSource = vm.Positions;
        }
    }

<Window x:Class="WpfApplication1.MyWin"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"        
        Title="MyWin" Height="300" Width="300">
    <Grid>
        <telerik:RadGridView x:Name="radGridView" AutoGenerateColumns="False">
            <telerik:RadGridView.Columns>
 
                <telerik:GridViewDataColumn Header="Name"  DataMemberBinding="{Binding Name}" TextAlignment="Left" Width="160"/>
                <telerik:GridViewComboBoxColumn  Header="Position"  DataMemberBinding="{Binding Position}" Width="*" />
            </telerik:RadGridView.Columns>
 
        </telerik:RadGridView>
    </Grid>
</Window>

 public partial class MyWin : Window
    {
        public MyWin()
        {
            InitializeComponent();
            this.WindowStartupLocation = System.Windows.WindowStartupLocation.CenterOwner;
 
            ViewModel vm = new ViewModel();
            this.radGridView.ItemsSource = vm.AllPlayers;
 
            GridViewComboBoxColumn combo = (GridViewComboBoxColumn)this.radGridView.Columns[1];
            combo.ItemsSource = vm.Positions;
        }
    }

<Application x:Class="WpfApplication1.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             StartupUri="MainWindow.xaml">
    <Application.Resources>
         
    </Application.Resources>
</Application>

    public partial class App : Application
    {
    }