1.标记WCF服务开启Session模式

[ServiceContract(SessionMode = SessionMode.Required)]

2.服务类添加ASPNETSESSION兼容标记

[System.ServiceModel.Activation.AspNetCompatibilityRequirements(RequirementsMode = System.ServiceModel.Activation.AspNetCompatibilityRequirementsMode.Required)]

3.配置WEB.CONFIG文件中<system.serviceModel>节
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true"></serviceHostingEnvironment>