or


<telerik:RadGridView IsFilteringAllowed="False" x:Name="PricingEcoList" ItemsSource="{Binding Path=TrancheDataCollection}" AutoGenerateColumns="False" SelectedItem="{Binding SelectedTranche, Mode=TwoWay}" FrozenColumnCount="4" AlternationCount="2" EnableRowVirtualization="True" Style="{DynamicResource RadGridViewStyle}" SelectionMode="Extended" Background="{DynamicResource DealOverViewBackGrndGrad}" HeaderRowStyle="{DynamicResource GridViewHeaderRowStyle}" telerik:StyleManager.Theme="Windows7" >
public class CustomerModel : _BaseModel { public int CustomerId { get; set; } public string CustomerCode { get; set; } public string CustomerName { get; set; } public List<ProjectModel> Projects { get; set; } } public class ProjectModel : _BaseModel { public int ProjectId { get; set; } public int UserId { get; set; } public int CustomerId { get; set; } public WarehouseModel PrimaryWarehouse { get; set; } public WarehouseModel SecondaryWarehouse { get; set; } public ProjectType ProjectType { get; set; } public string ProjectName { get; set; } public string ProjectNum { get; set; } public DateTime Date { get; set; } public string Comments { get; set; } }<Window.Resources> <DataTemplate x:Key="Project"> <TextBlock Text="{Binding ProjectName}" /> </DataTemplate> <HierarchicalDataTemplate x:Key="Customer" ItemTemplate="{StaticResource Project}" ItemsSource="{Binding Customers}"> <TextBlock Text="{Binding CustomerName}" /> </HierarchicalDataTemplate> </Window.Resources> <telerik:RadTreeView ItemsSource="{Binding Customers}" ItemTemplate="{StaticResource Customer}"/> 
