public ProjectUser projectuser { get; set; }
public int ProjectId { get; set; }

        <riaControls:DomainDataSource LoadedData="cashFlowDomainDataSource_LoadedData" x:Name="cashFlowDomainDataSource" 
                                      QueryName="GetCashFlowsQuery"  Style="{StaticResource DDS}">
            <riaControls:DomainDataSource.FilterDescriptors>
                <riaControls:FilterDescriptor Operator="IsEqualTo" PropertyPath="ProjectId" Value="{Binding ProjectId}" />
            </riaControls:DomainDataSource.FilterDescriptors>
        </riaControls:DomainDataSource>
 <toolkit:BusyIndicator IsBusy="{Binding ElementName=cashFlowDomainDataSource, Path=DomainContext.IsLoading}" >
            <toolkit:DataForm HorizontalAlignment="Left" Margin="12,12,0,0" x:Name="dataForm1" VerticalAlignment="Top" Height="198" Width="354"
                              AutoGenerateFields="True"  ItemsSource="{Binding ElementName=cashFlowDomainDataSource, Path=Data}" AutoEdit="False" EditEnding="dataForm1_EditEnding" AddingNewItem="dataForm1_AddingNewItem" BeginningEdit="dataForm1_BeginningEdit">
            </toolkit:DataForm>
          </toolkit:BusyIndicator>
        <Button x:Name="CancelButton" Content="Отмена" Click="CancelButton_Click" Width="75" Height="23" HorizontalAlignment="Right" Margin="0,12,0,0" Grid.Row="1" />
        <Button x:Name="OKButton" Content="ОК" Click="OKButton_Click" Width="75" Height="23" HorizontalAlignment="Right" Margin="0,12,79,0" Grid.Row="1" />

 private void dataForm1_EditEnding(object sender, DataFormEditEndingEventArgs e)
        {      ((CashFlow)(((DataForm)sender).CurrentItem)).ProjectUser = projectuser;    }

private void OKButton_Click(object sender, RoutedEventArgs e)
        {   this.DialogResult = true;
            dataForm1.CommitEdit();
            cashFlowDomainDataSource.SubmitChanges();   }

 private void button1_Click(object sender, RoutedEventArgs e)
        {var win = new CashFlowIDChildWindow2();
            ProjectUser proj = ProjectDataForm.CurrentItem as ProjectUser;
            win.ProjectId = proj.ProjectId;
            win.projectuser = proj;
            win.Show();}

<toolkit:DataForm AddingNewItem="dataForm1_AddingNewItem"> </toolkit:DataForm>

private void dataForm1_AddingNewItem(object sender, DataFormAddingNewItemEventArgs e)
        {
            
            int i ;
            //int i =  ((DataForm)sender);
            if (i > 5)
            {
                MessageBox.Show("Записей больше 5");
                e.Cancel = true;
            }
       }

<toolkit:DataForm AddingNewItem="dataForm1_AddingNewItem"> </toolkit:DataForm>

  private void dataForm1_AddingNewItem(object sender, DataFormAddingNewItemEventArgs e)
        {
            
            int i = ((DomainDataSourceView)((DataForm)sender).ItemsSource).Count;
            if (i > 5)
            {
                MessageBox.Show("Записей больше 5");
                e.Cancel = true;
            }
}

public int IdTender { get; set; }

<sdk:Label Content="Id Tender:" Grid.Column="0" Grid.Row="7" HorizontalAlignment="Left" Margin="3" VerticalAlignment="Center" />
<TextBox Grid.Column="1" Grid.Row="7" Height="23" HorizontalAlignment="Left" Margin="3" Name="idTenderTextBox" Text="{Binding 
Path=IdTender, Mode=TwoWay, NotifyOnValidationError=true, ValidatesOnExceptions=true, TargetNullValue=''}" VerticalAlignment="Center" 
Width="120" />

<Association Name="FK_ProjectUser_Tender">
          <End Type="u215600Model2.Tender" Role="Tender" Multiplicity="1" />
          <End Type="u215600Model2.ProjectUser" Role="ProjectUser" Multiplicity="*" />
          <ReferentialConstraint>
            <Principal Role="Tender">
              <PropertyRef Name="IdTender" />
            </Principal>
            <Dependent Role="ProjectUser">
              <PropertyRef Name="IdTender" />
            </Dependent>
          </ReferentialConstraint>
</Association>

public partial class u215600Entities2 : ObjectContext

[EnableClientAccess()]
    public class ProjectInOu : LinqToEntitiesDomainService<u215600Entities2>

public IQueryable<Tender> GetTenders()
public IQueryable<Tender> GetTendersUser()
public void InsertTender(Tender tender)
public void UpdateTender(Tender currentTender)
public void DeleteTender(Tender tender)

 <riaControls:DomainDataSource x:Name="pDomainDataSource"  />

<Button Name="button1" Command="{Binding ElementName=pDomainDataSource, Path=SubmitChangesCommand}"  />

IsEnabled="{Binding ElementName=pDomainDataSource, Path=???}"

<Button Content="Cинхронизация" Name="button2"  Grid.Row="2" Margin="3" IsEnabled="{Binding ElementName=button1, Path=IsEnabled, Converter={StaticResource NotOperatorValueConverter}}" />
        <Button Content="Cинхронизация" Name="button2"  Grid.Row="2" Margin="3" IsEnabled="{Binding ElementName=projectUserDomainDataSource, Path=HasChanges, Converter={StaticResource NotOperatorValueConverter}}" />

<toolkit:DataField Label="" Grid.Row="8" IsEnabled="{Binding Source={StaticResource DomainContext}, Path=HasChanges, Converter={StaticResource NotOperatorValueConverter}}">