Question

这是代码片段，我连接到我的WCF服务。

DefaultHttpClient client = new DefaultHttpClient();         
                            HttpGet request = new HttpGet(EMPLOYEE_LOG_IN);
                            request.setHeader("Accept", "application/json");
                            request.setHeader("Content-type", "application/json");          
                            HttpResponse response = client.execute(request);
                            HttpEntity entity = response.getEntity();
                            if(entity.getContentLength() != 0) {
                                Reader employeeReader = new InputStreamReader(response.getEntity().getContent());       
                                                //create a buffer to fill if from reader            
                                                char[] buffer = new char[(int) response.getEntity().getContentLength()];        
                                                //fill the buffer by the help of reader         
                                                employeeReader.read(buffer);                
                                                //close the reader streams              
                                                employeeReader.close(); 
                                                //for the employee json object              
                                                JSONObject employee =  new JSONObject(new String(buffer));
                                                Log.d("Response",employee.getString("FirstName"));

在不同情况下表现不同。这是我的WCF服务的代码

 public Controller GetEmployees(int personalNUmber)
        {                

                return new Controller
                            {
                                EmployeeId = 1,
                                FirstName = "FirstName",
                                LastName = "LastName"
                            };    
            }
        }

所以当我调用这个方法时一切正常，我得到了json格式，但是当我编辑了我的方法，并像这样连接到实体数据库

FineReceiptsTestEntities _entity = new FineReceiptsTestEntities();

        var t = _entity.Employees.FirstOrDefault(x => x.EmployeeID == personalNUmber);
        return new Controller
                   {

                       EmployeeId = 1,
                       FirstName = t != null ? t.Name : " ",
                       LastName = "LastName"
                   };

Json对象没有返回。仅返回错误的html内容，如此

服务器遇到处理请求的错误。请参阅服务帮助页面，用于构建对服务的有效请求。

但是浏览器中的这两种方法都可以正常工作并返回相关数据。

这是我的 web.config

<configuration>
  <system.web>
    <compilation debug="true" targetFramework="4.0">
      <assemblies>
        <add assembly="System.Data.Entity, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
      </assemblies>
    </compilation>
  </system.web>
  <system.serviceModel>
    <standardEndpoints>
      <webHttpEndpoint>
        <standardEndpoint helpEnabled="true" automaticFormatSelectionEnabled="true" />
      </webHttpEndpoint>
    </standardEndpoints>
    <services>
      <service name="dev_FineReceiptsService.ControllersInfo">
        <endpoint kind="webHttpEndpoint" contract="dev_FineReceiptsService.IControllersInfo" />
        <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" />
      </service>
    </services>
  </system.serviceModel>
  <connectionStrings>
    <add name="FineReceiptsTestEntities" connectionString="metadata=res://*/FineTest.csdl|res://*/FineTest.ssdl|res://*/FineTest.msl;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=msdev01;Initial Catalog=FineReceiptsTest;Integrated Security=True;MultipleActiveResultSets=True&quot;" providerName="System.Data.EntityClient" />
  </connectionStrings>
</configuration>

所以有人能告诉我使用Entity检索数据时会出现什么问题吗？

Answer 1

您的帖子中没有足够的信息来确定原因。您必须为任何人发布RAW HTTP响应以帮助您。由于您没有正确构建请求，服务器可能正在返回HTTP 415。

request.setHeader("Content-type", "application/json");

您正在为GET请求将内容类型设置为json。这是不可能的。服务器可能会尝试匹配它并感到困惑。也可能是服务器从请求中发出了真正的HTTP 500错误。从构造响应错误的方式来看，服务似乎在抱怨请求本身无效。

server encountered an error processing the request.Please see the service help page for constructing valid requests to the service.

如何使用Android消耗WCF Rest服务

1 个答案: