Syncfusion DomainDataGridControl Exercises

gistfile1.cs

public class MainPage
{
  public MainPage()
  {
    InitializeComponent();

    // throws NPE
    grid.Model.Grid.CurrentCellValidating +=Grid_CurrentCellValidating;

  }
}

MainPage.xaml

<UserControl
    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:syncfusionria="clr-namespace:Syncfusion.Windows.Controls.Grid.Ria;assembly=Syncfusion.Grid.Ria.Silverlight" 
    xmlns:syncfusion="clr-namespace:Syncfusion.Windows.Controls.Grid;assembly=Syncfusion.Grid.Silverlight"
    xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk" 
    xmlns:riaControls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.DomainServices"
    xmlns:web="clr-namespace:SilverlightSyncfusionGridTest.Web"
    x:Class="SilverlightSyncfusionGridTest.MainPage"
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">
    <UserControl.Resources>
        <web:SampleContext x:Key="SampleDomainContext" x:Name="SampleDomainContext" />
    </UserControl.Resources>
    <Grid x:Name="LayoutRoot" Background="White" >
        <Grid.RowDefinitions>
            <RowDefinition Height="11*"/>
            <RowDefinition Height="auto"/>
            <RowDefinition Height="auto"/>
        </Grid.RowDefinitions>

        <syncfusionria:DomainGridDataControl Content="DomainGridDataControl"
      			SourceType="web:Customer"                                          
      			x:Name="grid" 
      			AutoPopulateRelations="False" 
      			ShowGroupDropArea="True"   
      			RIASource="{Binding ElementName=dds}" 
      			LoadingText="Loading..." 
      			AutoPopulateColumns="False" 
      			ShowFilters="True" ColumnSizer="AutoWithLastColumnFill">
            <syncfusionria:DomainGridDataControl.VisibleColumns>

                <syncfusion:GridDataVisibleColumn
                    HeaderText="Full Name"                    
                    Binding="{Binding FullName, Mode=TwoWay}" />
                
                <syncfusion:GridDataVisibleColumn
                    HeaderText="Date of Birth"                   
                    Binding="{Binding DateOfBirth,Mode=TwoWay}" 
                    DataType="DateTime">
                    <syncfusion:GridDataVisibleColumn.ColumnStyle>
                        <syncfusion:GridDataColumnStyle CellType="DateTimeEdit" />
                    </syncfusion:GridDataVisibleColumn.ColumnStyle>
                </syncfusion:GridDataVisibleColumn>
                
                <syncfusion:GridDataIntegerEditVisibleColumn 
                    HeaderText="Number of Children" 
                    Binding="{Binding NumberOfChildren, Mode=TwoWay}"
                    DataType="NullableInt32"/>
                 
            </syncfusionria:DomainGridDataControl.VisibleColumns>
        </syncfusionria:DomainGridDataControl>


        <sdk:DataPager Source="{Binding Data, ElementName=dds}" 
			IsTotalItemCountFixed="True"
			PageSize="10" Grid.Row="1"/>

        <riaControls:DomainDataSource  x:Name="dds" 
			AutoLoad="True"
			QueryName="GetCustomers"                                       
			DomainContext="{StaticResource SampleDomainContext}" />
        <Button x:Name="SaveButton" Content="Save" HorizontalAlignment="Left" Margin="0,10,0,0" Grid.Row="2" VerticalAlignment="Top" Width="75" Click="SaveButton_Click"/>

    </Grid>
</UserControl>