SL 3 multi-table data display

This example shows how to display data in three tables of the link SL 3. The running result is as follows:

Shows the table relationship:

 
The data is displayed by calling the background service WCF, supporting data display;

The Background Service Code is as follows:

[ServiceContract (Namespace = "")] [AspNetCompatibilityRequirements (RequirementsMode = AspNetCompatibilityRequirementsMode. allowed)] public class DataServices {// Add more operations here and use [OperationContract] to mark them [OperationContract] public List <MERs> GetCustomerAll () {MyDataDataContext db = new MyDataDataContext (); return db. MERs. toList ();} [OperationContract] public List <MERs> GetCustomerByID (string CustomerID) {MyDataDataContext db = new MyDataDataContext (); var query = from customer in db. MERs where customer. customerID = CustomerID select customer; return query. toList ();} [OperationContract] public List <Orders> GetOrders (string customerID) {MyDataDataContext datacontext = new MyDataDataContext (); return (from order in datacontext. orders where order. customerID = customerID select order ). toList ();} [OperationContract] public List <Order_Details> GetOrderDetails (int orderID) {MyDataDataContext datacontext = new MyDataDataContext (); return (from orderdetail in datacontext. order_Details where orderdetail. orderID = orderID select orderdetail ). toList ();}}

The following code calls the WCF Service in the background:

DataServiceClient.DataServicesClient svc = new DataServiceClient.DataServicesClient();       public MainPage()       {           InitializeComponent();       }       private void lstCustomers_Loaded(object sender, RoutedEventArgs e)       {           this.txtStatus.Text = "Loading customers...";           svc.GetCustomerAllCompleted += new EventHandler<GetCustomerAllCompletedEventArgs>

(svc_GetCustomerAllCompleted);           svc.GetCustomerAllAsync();       }       void svc_GetCustomerAllCompleted(object sender, GetCustomerAllCompletedEventArgs e)       {           if (e.Error == null)           {               this.lstCustomers.ItemsSource = e.Result;               this.txtStatus.Text = string.Empty;           }           else           {               this.txtStatus.Text =                   "Error occurred while loading customers from database";           }       }       private void lstCustomers_SelectionChanged(object sender, SelectionChangedEventArgs e)       {           CAL.SLData.DataServiceClient.Customers selectedCustomer = this.lstCustomers.SelectedItem 

as CAL.SLData.DataServiceClient.Customers;           {               this.txtStatus.Text = "Loading orders...";               svc.GetOrdersCompleted +=                   delegate(object eventSender, GetOrdersCompletedEventArgs eventArgs)                   {                       if (eventArgs.Error == null)                       {                           this.dgOrders.ItemsSource = eventArgs.Result;                           this.txtStatus.Text = string.Empty;                       }                       else                       {                           this.txtStatus.Text =                               "Error occurred while loading orders from database";                       }                   };               svc.GetOrdersAsync(selectedCustomer.CustomerID);           }       }       private void dgOrders_SelectionChanged(object sender, EventArgs e)       {           CAL.SLData.DataServiceClient.Orders selectedOrder = this.dgOrders.SelectedItem as Orders;           if (selectedOrder != null)           {               this.txtStatus.Text = "Loading order details...";               svc.GetOrderDetailsCompleted +=                   (eventSender, eventArgs) =>                   {                       if (eventArgs.Error == null)                       {                           this.dgOrderDetails.ItemsSource = eventArgs.Result;                           this.txtStatus.Text = string.Empty;                       }                       else                       {                           this.txtStatus.Text =                               "Error occurred while loading order details from database";                       }                   };               svc.GetOrderDetailsAsync(selectedOrder.OrderID);           }       }       private void dgOrderDetails_AutoGeneratingColumn(object sender,

 DataGridAutoGeneratingColumnEventArgs e)       {           if (e.Column.Header.ToString() == "OrderID")               e.Column.Visibility = Visibility.Collapsed;       }

The UI Page code is as follows:

<Grid x:Name="LayoutRoot" Background="White">        <Grid.RowDefinitions>            <RowDefinition Height="55" x:Name="HeaderRow" />            <RowDefinition Height="*" x:Name="ContentRow"/>            <RowDefinition Height="20" x:Name="FooterRow"/>        </Grid.RowDefinitions>        <Grid.ColumnDefinitions>            <ColumnDefinition Width="*" />        </Grid.ColumnDefinitions>        <!-- Heading -->        <TextBlock x:Name="txtHeader" Grid.Row="0"                    FontSize="20" Margin="5,5" Foreground="Blue"                   Text="My First Data Application in Silverlight">        </TextBlock>        <!-- A textblock in the footer to be used as an Status bar -->        <TextBlock x:Name="txtStatus" Grid.Row="2"                FontSize="10" Margin="5,0" Foreground="Red">        </TextBlock>        <!-- Content Holder -->        <Grid x:Name="ContentGrid" Grid.Row="1" Margin="5">            <Grid.RowDefinitions>                <RowDefinition Height=".6*" />                <RowDefinition Height=".4*" />            </Grid.RowDefinitions>            <Grid.ColumnDefinitions>                <ColumnDefinition Width="200" />                <ColumnDefinition Width="*" />            </Grid.ColumnDefinitions>            <!-- Listbox for displaying customers -->            <ListBox x:Name="lstCustomers" Grid.Column="0" Grid.RowSpan="2"                     DisplayMemberPath="ContactName"                     Loaded="lstCustomers_Loaded"                     SelectionChanged="lstCustomers_SelectionChanged">            </ListBox>            <!-- DataGrid for displaying orders of a customer                 (with autogenerated columns) -->            <data:DataGrid x:Name="dgOrders" Grid.Row="0" Grid.Column="1"                            AutoGenerateColumns="True"                           SelectionChanged="dgOrders_SelectionChanged">            </data:DataGrid>            <!-- DataGrid for displaying orderdetais for an order -->            <data:DataGrid x:Name="dgOrderDetails" Grid.Row="1" Grid.Column="1"                            AutoGenerateColumns="True"                           AutoGeneratingColumn="dgOrderDetails_AutoGeneratingColumn">            </data:DataGrid>        </Grid>    </Grid>