如何在 WCF 中使用 HTTP 发送 System.IO.Stream 转换为对象？

Question

我有一个非常简单的 WCF 程序，其中有一个简单的自主机和一个在同一台计算机上运行的客户端。有一个方法返回 System.IO.Stream，它实际上是简单字符串的序列化形式。 （这可以是任意数量的数据类型，但暂时我们将其视为字符串）。

以下是我使用的代码，如果您想看一下。 SerializeData() 和 DeserializeData() 就是用于执行此操作的方法，并且工作正常。

主机服务： <代码>

namespace HelloWCF1
{
    [ServiceContract(Namespace = "http://My.WCF.Samples")]
    public interface IService1
    {
        [OperationContract]
        Stream GetString();
    }

public class Service1 : IService1
{
    //Simple String
    public Stream GetString()
    {
        string str = "ABC";

        Stream ms = new MemoryStream();
        SerializeData<string>(str, ms);

        return ms;
    }

    /// <summary>
    /// Serialize an object of the type T to a Stream
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="objectToSerialize"></param>
    /// <param name="str"></param>
    public void SerializeData<T>(T objectToSerialize, Stream str)
    {
        BinaryFormatter bf = new BinaryFormatter();

        try
        {
            bf.Serialize(str, objectToSerialize);
            str.Position = 0;
        }
        catch (Exception)
        {
        }
    }

    /// <summary>
    /// Deserialize a Stream
    /// </summary>
    /// <param name="dataToDeserialize"></param>
    /// <returns></returns>
    public object DeserializeData(Stream dataToDeserialize)
    {
        BinaryFormatter bf = new BinaryFormatter();
        object ret = null;

        try
        {
            ret = bf.Deserialize(dataToDeserialize);
        }
        catch (Exception)
        {
        }

        return ret;
    }
}

class Program
{
    static void Main(string[] args)
    {
        Uri baseAddr = new Uri("http://localhost:8000/WCFSampleService");

        //ServiceHost is created by defining Service Type and Base Address
        using (ServiceHost svcHost = new ServiceHost(typeof(Service1), baseAddr))
        {

            //Trace message for service start
            Console.WriteLine("Service Starting...");

            //Adding an end point
            svcHost.AddServiceEndpoint(typeof(IService1), new BasicHttpBinding(), "HelloWCF");

            //Open service host
            svcHost.Open();

            Console.WriteLine("Press [Enter] to terminate.");
            Console.ReadLine();

            //Close service host
            svcHost.Close();
        }
    }
}

<代码>}

客户端程序：

命名空间客户端 { [ServiceContract(命名空间 = "http://My.WCF.Samples")] 公共接口IService1 { 【运营合同】 流 GetString(); }

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private IService1 proxy = null;
    private Stream memStr = new MemoryStream();

    private void button1_Click(object sender, EventArgs e)
    {
        //Create end point
        EndpointAddress epAddr = new EndpointAddress("http://localhost:8000/WCFSampleService/HelloWCF");

        //Create proxy
        proxy = ChannelFactory<IService1>.CreateChannel(new BasicHttpBinding(), epAddr);

        //WCF Service Method is called to aquire the stream
        try
        {
            memStr = proxy.GetString();
            string str = (string)DeserializeData(memStr);
            MessageBox.Show(str);
        }
        catch (CommunicationException commEx)
        {
            MessageBox.Show("Service Call Failed：" + commEx.Message);
        }
    }       

    /// <summary>
    /// Serialize an object of the type T to a Stream
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="objectToSerialize"></param>
    /// <param name="str"></param>
    public static void SerializeData<T>(T objectToSerialize, Stream str)
    {
        BinaryFormatter bf = new BinaryFormatter();

        try
        {
            bf.Serialize(str, objectToSerialize);
            str.Position = 0;
        }
        catch (Exception)
        {
        }
    }

    /// <summary>
    /// Deserialize a Stream
    /// </summary>
    /// <param name="dataToDeserialize"></param>
    /// <returns></returns>
    public static object DeserializeData(Stream dataToDeserialize)
    {
        BinaryFormatter bf = new BinaryFormatter();
        object ret = null;

        try
        {
            ret = bf.Deserialize(dataToDeserialize);
        }
        catch (Exception)
        {
        }

        return ret;
    }
}

<代码>}

现在，效果很好。它将字符串序列化为 Stream，并使用 HTTP 发送，效果非常好。但是，我需要在发送之前将此 Stream 转换或转换为对象。简而言之，我需要 GetString() 方法如下所示：

公共对象 GetString() { 字符串 str = "ABC";

        Stream ms = new MemoryStream();

        SerializeData<string>(str, ms);

        return (object)ms;

}

但是，当我这样做时，在 Button1_Click 事件内，在 ***memStr = proxy.GetString();*** 行，我得到一个通信异常。我在日语操作系统中工作，所以我收到的异常消息是日语的，所以我会尽力翻译成英语。如果不是很清楚，请原谅我。

***Error occured in the reception of HTTP response concerning [url]http://localhost:8000/WCFSampleService/HelloWCF[/url]. Cause of the error could be Service End Point binding is not using an HTTP protocol. Or as a different cause, it is also possible that HTTP request context is suspended according to the server (as in the case of server being shut down). Please refer the server log for more details.***

问题到底是什么？如何让程序按我想要的方式工作？它说要查看日志文件，但我在哪里可以找到它们？

提前致谢！

Answer 1

直接返回字符串不是更好吗？当然，通过 Http 绑定作为流返回的字符串将被 Base64 编码，这通常会使返回的数据大小加倍！

也许您可以考虑将 TcpBinding 作为替代方案。