Question

我正在将客户端发送的对象添加到服务中的列表，我的问题是这样，在调试期间我看到，只要我从主服务返回到客户端，列表就会变为0。＆＃ 39; s就像列表被清空一样，一旦程序流程返回到客户端，然后当客户端向服务发送数据时数据就在那里，一旦我输入服务方法，列表就会被填充用旧数据。我想从程序的另一部分访问这些数据，但我总是看到列表为空。有什么提示吗？

Answer 1

根据我的评论，您需要设置ServiceContract＆＃39; SessionMode以及ServiceBehavior＆＃39; InstanceContextMode。默认InstanceContextMode为PerCall，这意味着您的列表不会被保留。您需要将其更改为使用PerSession。请参阅下面的完整工作示例（.NET 4）：

服务端代码：

using System.Collections.Generic;
using System.ServiceModel;

namespace WcfService1
{
    [ServiceContract(SessionMode = SessionMode.Required)]
    public interface IService1
    {
        [OperationContract]
        int AddData(string data);

        [OperationContract]
        List<string> GetData();
    }

    [ServiceBehavior(InstanceContextMode = InstanceContextMode.PerSession)]
    public class Service1 : IService1
    {
        private readonly List<string> _myList = new List<string>();

        public int AddData(string data)
        {
            _myList.Add(data);
            return _myList.Count;
        }

        public List<string> GetData()
        {
            return _myList;
        }
    }
}

服务端web.config

<?xml version="1.0"?>
<configuration>

  <system.web>
    <compilation debug="true" targetFramework="4.0" />
  </system.web>
  <system.serviceModel>

    <protocolMapping>
      <add scheme="http" binding="wsHttpBinding"/>
    </protocolMapping>

    <behaviors>
      <serviceBehaviors>
        <behavior>
          <serviceMetadata httpGetEnabled="true"/>
          <serviceDebug includeExceptionDetailInFaults="true"/>
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <serviceHostingEnvironment multipleSiteBindingsEnabled="true" />
  </system.serviceModel>
 <system.webServer>
    <modules runAllManagedModulesForAllRequests="true"/>
    <directoryBrowse enabled="true"/>
  </system.webServer>

</configuration>

客户端：

using System;
using System.Collections.Generic;
using ConsoleApplication1.ServiceReference1;

namespace ConsoleApplication1
{
    internal class Program
    {
        private static void Main()
        {
            using (var service = new Service1Client())
            {
                // Add items...
                int itemCount;
                itemCount = service.AddData("Test Item 1");
                Console.WriteLine("Service now holds {0} items", itemCount);
                itemCount = service.AddData("Test Item 2");
                Console.WriteLine("Service now holds {0} items", itemCount);
                itemCount = service.AddData("Test Item 3");
                Console.WriteLine("Service now holds {0} items", itemCount);

                // Get all of the items added...
                List<string> listFromService = service.GetData();
                foreach (var listItem in listFromService)
                {
                    Console.WriteLine("  * {0}", listItem);
                }
                Console.WriteLine();
            }
            Console.ReadKey();
        }
    }
}

客户端app.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <system.serviceModel>
        <bindings>
            <wsHttpBinding>
                <binding name="WSHttpBinding_IService1" />
            </wsHttpBinding>
        </bindings>
        <client>
            <endpoint address="http://localhost:59604/Service1.svc" binding="wsHttpBinding"
                bindingConfiguration="WSHttpBinding_IService1" contract="ServiceReference1.IService1"
                name="WSHttpBinding_IService1">
            </endpoint>
        </client>
    </system.serviceModel>
</configuration>

注意：我必须确保wsHttpBinding被basicHttpBinding用作 NOT 支持会话。

wcf数据发生了什么？

1 个答案: