关于Silverlight调用天气预报接口问题

问题：因Silverlight客户端不能直接调用webservice接口（外网天气接口），调用会出现跨域访问的问题，即使添加了跨域文件也不好使。解决方法如下

解决方法一：1.在服务端建立一个wcf服务端，在wcf里调用webservice接口（外网天气接口）

wcf服务接口IWeatherService.cs

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Runtime.Serialization;
 using System.ServiceModel;
 using System.Text;

 namespace WcfServiceWeather
 {
     // 注意: 使用“重构”菜单上的“重命名”命令，可以同时更改代码和配置文件中的接口名“IWeatherService”。
     [ServiceContract]
     public interface IWeatherService
     {
         [OperationContract]
         string[] GetCityWeather(string CityName);
     }
 }

wcf服务实现类WeatherService.cs

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Runtime.Serialization;
 using System.ServiceModel;
 using System.Text;

 namespace WcfServiceWeather
 {
     // 注意: 使用“重构”菜单上的“重命名”命令，可以同时更改代码、svc 和配置文件中的类名“WeatherService”。
     // 注意: 为了启动 WCF 测试客户端以测试此服务，请在解决方案资源管理器中选择 WeatherService.svc 或 WeatherService.svc.cs，然后开始调试。
     public class WeatherService : IWeatherService
     {
         public string[] GetCityWeather(string CityName)
         {
             ServiceRefWeather.WeatherWebServiceSoapClient client = new ServiceRefWeather.WeatherWebServiceSoapClient("WeatherWebServiceSoap");
             string[] cityNameWeather = client.getWeatherbyCityName(CityName);
             return cityNameWeather;
         }
     }
 }

添加完成后预览服务，将会在配置文件中自动生成相应的配置system.serviceModel

 <?xml version="1.0" encoding="utf-8"?>
 <configuration>

   <appSettings>
     <add key="aspnet:UseTaskFriendlySynchronizationContext" value="true" />
   </appSettings>
   <system.web>
     <compilation debug="true" targetFramework="4.5" />
     <httpRuntime targetFramework="4.5"/>
   </system.web>
   <system.serviceModel>
     <bindings>
       <basicHttpBinding>
         <binding name="WeatherWebServiceSoap" />
       </basicHttpBinding>
       <customBinding>
         <binding name="WeatherWebServiceSoap12">
           <textMessageEncoding messageVersion="Soap12" />
           <httpTransport />
         </binding>
       </customBinding>
     </bindings>
     <client>
       <endpoint address="http://www.webxml.com.cn/WebServices/WeatherWebService.asmx"
         binding="basicHttpBinding" bindingConfiguration="WeatherWebServiceSoap"
         contract="ServiceRefWeather.WeatherWebServiceSoap" name="WeatherWebServiceSoap" />
       <endpoint address="http://www.webxml.com.cn/WebServices/WeatherWebService.asmx"
         binding="customBinding" bindingConfiguration="WeatherWebServiceSoap12"
         contract="ServiceRefWeather.WeatherWebServiceSoap" name="WeatherWebServiceSoap12" />
     </client>
     <behaviors>
       <serviceBehaviors>
         <behavior>
           <!-- 为避免泄漏元数据信息，请在部署前将以下值设置为 false -->
           <serviceMetadata httpGetEnabled="true" httpsGetEnabled="true"/>
           <!-- 要接收故障异常详细信息以进行调试，请将以下值设置为 true。在部署前设置为 false 以避免泄漏异常信息 -->
           <serviceDebug includeExceptionDetailInFaults="false"/>
         </behavior>
       </serviceBehaviors>
     </behaviors>
     <protocolMapping>
         <add binding="basicHttpsBinding" scheme="https" />
     </protocolMapping>
     <serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true" />
   </system.serviceModel>
   <system.webServer>
     <modules runAllManagedModulesForAllRequests="true"/>
     <!--
         若要在调试过程中浏览 Web 应用程序根目录，请将下面的值设置为 True。
         在部署之前将该值设置为 False 可避免泄露 Web 应用程序文件夹信息。
       -->
     <directoryBrowse enabled="true"/>
   </system.webServer>

 </configuration>

2.Silverlight客户端添加服务引用（此处添加的是wcf的服务引用）

 ServiceReference1.WeatherServiceClient client = new ServiceReference1.WeatherServiceClient();
                 client.GetCityWeatherCompleted += (s, e) =>
                 {
                     try
                     {
                         if (e.Error == null)
                         {
                             var result=e.Result;//此处处理结果就ok了
                          }
                     catch (Exception ex)
                     {
                         lbltitle1.Content = ex.Message;
                     }

                 };
                 client.GetCityWeatherAsync("北京");

3.添加跨域文件clientaccesspolicy.xml

 <?xml version="1.0" encoding="utf-8" ?>
 <access-policy>
   <cross-domain-access>
     <policy>
       <allow-from http-request-headers="*">
         <domain uri="*"/>
       </allow-from>
       <grant-to>
         <resource include-subpaths="true" path="/"/>
       </grant-to>
     </policy>
   </cross-domain-access>
 </access-policy>

crossdomain.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE cross-domain-policy SYSTEM "http://www.macromedia.com/xml/dtds/cross-domain-policy.dtd" >
 <cross-domain-policy>
   <site-control permitted-cross-domain-policies="all" />
   <allow-access-from domain="*" />
   <allow-http-request-headers-from domain="*" headers="*"/>
 </cross-domain-policy>

解决方法二：直接在Silverlight的web中添加wcf无法文件、添加（外网天气服务接口）处理天气接口，然后在客户端直接调用自己创建的wcf，此时客户端会产生一个ServiceReferences.ClientConfig的文件

 <configuration>
     <system.serviceModel>
         <bindings>
             <basicHttpBinding>
                 <binding name="BasicHttpBinding_IWeatherService" maxBufferSize=""
                     maxReceivedMessageSize="">
                     <security mode="None" />
                 </binding>
             </basicHttpBinding>
         </bindings>
         <client>
             <endpoint address="http://192.168.0.161:8080/bjsw/WCF/WeatherService.svc"
                 binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding_IWeatherService"
                 contract="ServiceReference1.IWeatherService" name="BasicHttpBinding_IWeatherService" />
         </client>
     </system.serviceModel>
 </configuration>

在客户端直接调用就ok了