Silverlight专题（16）- 动态设置WCF Service配置信息

问题：

在Silverlight中是使用ServiceReferences.ClientConfig文件来保存和查看WCF服务的相对信息的

而ServiceReferences.ClientConfig又是包含在.xap文件中的

这样就导致如果您的Silverlight工程有用到WCF服务就需要在每次部署到不同网站的时候重新更改下WCF的配置并重新编译

而且这个重新配置的过程又往往可能需要Visual Studio 2008的帮助来重新链接WCF服务

而且对于有些部署的服务器就可能非常不现实了（有的服务器要求系统干净，不允许安装其他软件）

那么怎么办呢？

解决方案：

首先让我们来创建一个含有WCF Service的Silverlight工程

并在Web工程中添加一个Silverlight-enabled WCF Service如下

并在其中加入如下代码用于存储产品信息（包括Name名字、Description描述、Price价格）：

   1: [DataContract]

   2: public class ProductInfo

   3: {

   4:     [DataMember]

   5:     public string Name;

   6:  

   7:     [DataMember]

   8:     public double Price;

   9:  

  10:     [DataMember]

  11:     public string Description;

  12: }

而其OperateContract为

   1: [ServiceContract(Namespace = "")]

   2: [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]

   3: public class ProductService

   4: {

   5:     [OperationContract]

   6:     public List<ProductInfo> RetreiveData()

   7:     {

   8:         List<ProductInfo> products=new List<ProductInfo>();

   9:         for (int i = 0; i < 8; i++)

  10:         {

  11:             products.Add(new ProductInfo()

  12:                              {

  13:                                  Name = "Product " + (i + 1),

  14:                                  Price = 30.5*(i+1),

  15:                                  Description = "Product "+(i+1)+" for test"

  16:                              }

  17:             );

  18:         }

  19:         // Add your operation implementation here

  20:         return products;

  21:     }

  22: }

用来以WCF Service的形式将数据库中的数据（这里为方便期间用了伪数据）传给Silverlight客户端

首先给Silverlight工程添加Service References

我们在Silverlight客户端这边以ListBox的形式呈现出来，定义如下（Page.xaml文件中）

   1: <ListBox x:Name="ProductLBCtl" HorizontalAlignment="Center" VerticalAlignment="Top" Background="Transparent" BorderThickness="0">

   2:     <ListBox.ItemTemplate>

   3:         <DataTemplate>

   4:             <StackPanel Orientation="Horizontal">

   5:                 <ContentPresenter Content="{Binding Name}" Margin="10,0"/>

   6:                 <ContentPresenter Content="{Binding Description}" Margin="10,0"/>

   7:                 <ContentPresenter Content="{Binding Price}" Margin="10,0"/>

   8:             </StackPanel>

   9:         </DataTemplate>

  10:     </ListBox.ItemTemplate>

  11: </ListBox>

获取WCF Service的数据信息如下（Page.xaml.cs中）

   1: public Page()

   2: {

   3:     InitializeComponent();

   4:     this.Loaded += new RoutedEventHandler(Page_Loaded);

   5: }

   6:  

   7: void Page_Loaded(object sender, RoutedEventArgs e)

   8: {

   9:     ProductServiceClient client=new ProductServiceClient();

  10:     this.Cursor = Cursors.Hand;

  11:     client.RetreiveDataAsync();

  12:     client.RetreiveDataCompleted += (sender2, e2) =>

  13:                                         {

  14:                                             if (e2.Cancelled == false && e2.Error == null)

  15:                                             {

  16:                                                 ObservableCollection<ProductInfo> products = e2.Result;

  17:                                                 this.ProductLBCtl.ItemsSource = products;

  18:                                                 this.Cursor = Cursors.Arrow;

  19:                                             }

  20:                                         };

  21: }

这样我们就可以获得到WCF Service传过来的数据了

部署时由于WCF Service的部署地址不同，将需要我们重新索引，并编译这个程序，非常繁琐

你可以采用如下的动态配置的方式一举解决这个问题：

删除ServiceReferences.ClientConfig文件,并在Silverlight 工程下添加一个类文件(Class File)ServiceUtil.cs如下

   1: public static ProductServiceClient GetDynamicClient()

   2: {

   3:     BasicHttpBinding binding = new BasicHttpBinding(

   4:     Application.Current.Host.Source.Scheme.Equals("https", StringComparison.InvariantCultureIgnoreCase) 

   5:     ? BasicHttpSecurityMode.Transport : BasicHttpSecurityMode.None);

   6:     binding.MaxReceivedMessageSize = int.MaxValue;

   7:     binding.MaxBufferSize = int.MaxValue;

   8:     return new ProductServiceClient(binding, new EndpointAddress(

   9:         new Uri(Application.Current.Host.Source, "../ProductService.svc")));

  10: }

上述就是通过动态的形式获取得到ProductService了

修改Page.xaml.cs文件如下

   1: void Page_Loaded(object sender, RoutedEventArgs e)

   2: {

   3:     ProductServiceClient client = ServiceUtil.GetDynamicClient();//动态获取ProductServiceClient

   4:     this.Cursor = Cursors.Hand;

   5:     client.RetreiveDataAsync();

   6:     client.RetreiveDataCompleted += (sender2, e2) =>

   7:                                         {

   8:                                             if (e2.Cancelled == false && e2.Error == null)

   9:                                             {

  10:                                                 ObservableCollection<ProductInfo> products = e2.Result;

  11:                                                 this.ProductLBCtl.ItemsSource = products;

  12:                                                 this.Cursor = Cursors.Arrow;

  13:                                             }

  14:                                         };

  15: }

这样大家就可以在不用修改的情况下非常便捷的部署到IIS或者Apache上了

代码下载：