Interesting Issue with Silverlight Datagrid - silverlight

Question

Folks,
I'm having an interesting issue with Silverlight DataGrid data binding. It may be b/c I'm not binding the data source properly. Here's the object & the observable collection
/// <summary>
/// Interface for all model elements
/// </summary>
public interface IBaseModel
{
}
/// <summary>
/// Employee model
/// </summary>
public class EmployeeModel : IBaseModel
{
public string FirstName { get; set; }
public string LastName { get; set; }
public override string ToString()
{
return FirstName + LastName;
}
}
// The observable collection is loaded and bound in the user control
public partial class EmployeeMasterDetailsWindow : UserControl
{
public EmployeeMasterDetailsWindow()
{
try
{
InitializeComponent();
ObservableCollection<IBaseModel> k = new ObservableCollection<IBaseModel>()
{new EmployeeModel(){FirstName="Frodo",
LastName=" Baggins"},
new EmployeeModel(){FirstName="Pippin",
LastName="Thomas"},
new EmployeeModel(){FirstName="John",
LastName="Doe"},
new EmployeeModel(){FirstName="Tim",
LastName="Kiriev"}};
dataGrid1.DataContext = k;
CustomersListBox.DataContext = k;
}
catch (Exception ex)
{
}
}
}
//here's the XAML
<UserControl x:Class="AdventureWorksManagement.UI.EmployeeMasterDetailsWindow"
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="379" d:DesignWidth="516"
xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk"
xmlns:toolkit="http://schemas.microsoft.com/winfx/2006/xaml/presentation/toolkit">
<UserControl.Resources>
<DataTemplate x:Key="CustomerTemplate">
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding FirstName}" />
<TextBlock Text=" " />
<TextBlock Text="{Binding LastName}" />
</StackPanel>
</DataTemplate>
</UserControl.Resources>
<Grid x:Name="LayoutRoot" Background="White" Height="371" Width="595">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="312*" />
<ColumnDefinition Width="283*" />
</Grid.ColumnDefinitions>
<sdk:DataGrid Height="325" HorizontalAlignment="Left"
Margin="12,12,0,0" Name="dataGrid1" VerticalAlignment="Top" Width="271" ItemsSource="{Binding}"
RowDetailsTemplate="{StaticResource CustomerTemplate}">
</sdk:DataGrid>
<ListBox x:Name="CustomersListBox"
Margin="10,10,10,11"
ItemsSource="{Binding}"
ItemTemplate="{StaticResource CustomerTemplate}" />
</Grid>
The Listbox shows all the of the employees, but the DataGrid doesn't. I don't even see the DataGrid. I see this error message in the output window:
'System.Collections.ObjectModel.ObservableCollection1[AdventureWorksManagement.Model.IBaseModel]'
'System.Collections.ObjectModel.ObservableCollection1[AdventureWorksManagement.Model.IBaseModel]'
(HashCode=54025633).
BindingExpression: Path='FirstName'
DataItem='System.Collections.ObjectModel.ObservableCollection`1[AdventureWorksManagement.Model.IBaseModel]'
(HashCode=54025633); target element is
'System.Windows.Controls.TextBlock'
(Name=''); target property is 'Text'
(type 'System.String')..
What could I be doing wrong?

Answer 1

By making it an ObservableCollection<IBaseModel> you are effectively casting all the child objects to IBaseModel, which has no members.
In this instance make it an ObservableCollection<EmployeeModel>.