WCF JSON和AspnetCompatibility的配置

在WCF Service Application中加入<enableWebScript>

<system.serviceModel>
   <behaviors>
      <endpointBehaviors>
         <behavior name="ajaxbehavior">
            <enableWebScript />
         </behavior>
      </endpointBehaviors>
   </behaviors>
   <services>
      <service name="JsonWCF.StudentService">
         <endpoint binding="webHttpBinding" contract="JsonWCF.IStudentService" behaviorConfiguration="ajaxbehavior" />
      </service>
   </services>
</system.serviceModel>

定义Contract，添加[WebGet] Attribute允许HTTP Get访问

[ServiceContract]
   public interface IStudentService
   {
      [OperationContract]
      [WebGet]      
      Student RandomStudent();
   }

   [DataContract]
   public class Student
   {
      [DataMember]
      public string FirstName { get; set; }

      [DataMember]
      public string LastName { get; set; }

      [DataMember]
      public DateTime DOB { get; set; }
   }

ASP.NET Compatibility

WCF可以以ASP.NET的方式host，这样就可以使用httpmodule httpcontext等一些asp.net特有的流程

在配置文件中添加

<system.serviceModel>
   <serviceHostingEnvironment aspNetCompatibilityEnabled="true" />
   ...

定义Module (Namespace = JsonWCF)

public class MyModule : IHttpModule
   {
      public void Dispose()
      {
         
      }

      public void Init(HttpApplication context)
      {
         context.BeginRequest += context_BeginRequest;
      }

      void context_BeginRequest(object sender, EventArgs e)
      {
         HttpContext.Current.Application["key"] = "nothing is impossible";
      }
   }

web.config添加module

<system.web>
      <httpModules>
         <add name="mymodule" type="JsonWCF.MyModule"/>
...

实现中就可以访问HttpApplication，注意需要为service标记AspNetCompatibilityRequirements，表示允许通过asp.net的方式访问

[AspNetCompatibilityRequirements(
      RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
   public class StudentService : IStudentService
   {
      public Student RandomStudent()
      {
         string firstname = "null";         
         if (HttpContext.Current != null)
            firstname = HttpContext.Current.Application["key"] as string;
         return new Student { DOB = DateTime.Parse("1983/10/14"), FirstName = firstname, LastName = "Zhu" };
      }
   }

Remarks
如果将配置中的aspnetcompatibilityenabled改为false，wcf将不再走aspnet管道，application始终为空