SL 3 多表資料顯示

本樣本是一個關係SL 3 三張表資料的顯示問題,運行結果如下所示:

表關係如所示:

 
這些資料的顯示都是通過調用後台服務WCF,支援資料顯示;

後台服務代碼如下所示:

[ServiceContract(Namespace = "對外提供資料服務")]   [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]   public class DataServices   {       // 在此處添加更多操作並使用 [OperationContract] 標記它們       [OperationContract]       public List<Customers> GetCustomerAll()       {           MyDataDataContext db = new MyDataDataContext();           return db.Customers.ToList();       }       [OperationContract]       public List<Customers> GetCustomerByID(string CustomerID)       {           MyDataDataContext db = new MyDataDataContext();           var query = from customer in db.Customers                       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();       }   }

後台調用WCF服務代碼如下:

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;       }

UI 頁面代碼如下所示:

<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>