c# - 通过WCF服务上传超过50KB的文件失败

Question

我正在尝试通过 WCF 服务进行文件上传/下载。传输协议(protocol)是HTTP。我已将绑定(bind)设置为用户 Streaming 作为传输模式，并尝试了几天以使其正常工作，但没有成功。我已经设法让它适用于小文件。上传大文件时，会在服务器上创建文件，写入大量字节，然后事务失败。

该服务托管在 Windows Azure WebRole 环境中，该环境的扩展程度必须足以完成任务。

当使用 SvcTraceViewer.exe 检查(e2e-file)跟踪日志时，问题似乎是这样的:

An exception has been thrown when reading the stream.

与调用堆栈:

System.ServiceModel.Dispatcher.StreamFormatter.MessageBodyStream.Read(Byte[] buffer, Int32 offset, Int32 count)
DataService.TransferService.UploadFile(RemoteFileInfo request)
SyncInvokeUploadImage(Object , Object[] , Object[] )
System.ServiceModel.Dispatcher.SyncMethodInvoker.Invoke(Object instance, Object[] inputs, Object[]& outputs)
System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc& rpc)
System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc& rpc)
System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage31(MessageRpc& rpc)
System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)

服务契约(Contract)如下所示:

[ServiceContract]
public interface ITransferService
{
    [OperationContract]
    RemoteFileInfo DownloadImage(DownloadRequest request);

    [OperationContract(IsOneWay = true)]
    void UploadImage(RemoteFileInfo request);
}

[MessageContract]
public class DownloadRequest
{
    [MessageBodyMember]
    public string FileName;
}

[MessageContract]
public class RemoteFileInfo : IDisposable
{
    [MessageHeader(MustUnderstand = true)] 
    public string FileName;

    [MessageHeader(MustUnderstand = true)] 
    public long Length;

    [MessageBodyMember(Order = 1)] 
    public System.IO.Stream FileByteStream;

    public void Dispose()
    {
        if (FileByteStream != null)
        {
            FileByteStream.Close();
            FileByteStream = null;
        }
    }
}

这是服务实现:

public class TransferService : ITransferService
{
    public RemoteFileInfo DownloadImage(DownloadRequest request)
    {
        return DownloadFile(request);            
    }

    public void UploadImage(RemoteFileInfo request)
    {            
        UploadFile(request);
    }

    public RemoteFileInfo DownloadFile(DownloadRequest request)
    {
        var result = new RemoteFileInfo();
        try
        {
            var filePath = Path.Combine(RoleEnvironment.GetLocalResource("TempStorage").RootPath, request.FileName);
            var fileInfo = new FileInfo(filePath);

            if (!fileInfo.Exists)
                throw new FileNotFoundException("File not found", request.FileName);

            var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read);

            result.FileName = request.FileName;
            result.Length = fileInfo.Length;
            result.FileByteStream = stream;
        }
        catch (Exception ex)
        {
        }
        return result;
    }

    public void UploadFile(RemoteFileInfo request)
    {
        FileStream targetStream;
        var sourceStream = request.FileByteStream;

        var filePath = Path.Combine(RoleEnvironment.GetLocalResource("TempStorage").RootPath, request.FileName);

        using (targetStream = new FileStream(filePath, FileMode.Create, FileAccess.Write, FileShare.None))
        {
            const int bufferLen = 65000;
            var buffer = new byte[bufferLen];
            var count = 0;
            while ((count = sourceStream.Read(buffer, 0, bufferLen)) > 0)
            {
                targetStream.Write(buffer, 0, count);
            }
            targetStream.Close();
            sourceStream.Close();
        }
    }
}

我已经像这样设置 WCF 服务的 web.config 以启用流式传输，增加相关的大小限制(或至少是我知道的)和超时:

<?xml version="1.0"?>
<configuration>
  <system.diagnostics>
    <trace autoflush="true">
        <listeners>
          <add type="Microsoft.WindowsAzure.Diagnostics.DiagnosticMonitorTraceListener, Microsoft.WindowsAzure.Diagnostics, Version=2.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
            name="AzureDiagnostics">
            <filter type="" />
          </add>
        </listeners>
    </trace>
    <sources>
      <source name="System.ServiceModel"
              switchValue="Information, ActivityTracing"
              propagateActivity="true">
        <listeners>
          <add name="sdt"
              type="System.Diagnostics.XmlWriterTraceListener"
              initializeData= "log.e2e" />
        </listeners>
      </source>
    </sources>
  </system.diagnostics>
  <system.web>
    <customErrors mode="Off" />
    <compilation debug="true" targetFramework="4.0" />
    <httpRuntime maxRequestLength="2097151" useFullyQualifiedRedirectUrl="true" executionTimeout="14400"   />
  </system.web>
  <system.serviceModel>
    <behaviors>
      <serviceBehaviors>
        <behavior>
          <serviceMetadata httpGetEnabled="true"/>
          <serviceDebug includeExceptionDetailInFaults="false"/>
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <serviceHostingEnvironment multipleSiteBindingsEnabled="true" />

    <bindings>
      <basicHttpBinding>
        <binding closeTimeout="00:01:00" 
                 openTimeout="00:01:00" 
                 receiveTimeout="00:10:00"
                 sendTimeout="00:10:00" 
                 maxReceivedMessageSize="2147483647"
                 maxBufferSize="2147483647" 
                 transferMode="Streamed" >
          <readerQuotas maxDepth="2147483647" 
                        maxStringContentLength="2147483647"
                        maxArrayLength="2147483647"
                        maxBytesPerRead="2147483647"
                        maxNameTableCharCount="2147483647"/>
        </binding>
      </basicHttpBinding>
    </bindings>

  </system.serviceModel>
  <system.webServer>
    <modules runAllManagedModulesForAllRequests="true"/>
    <directoryBrowse enabled="true"/>
  </system.webServer>

</configuration>

客户端是一个WPF应用程序。调用代码是这样的:

private void UploadImage(byte[] data, Guid guid)
{
    using (var transferService = new TransferServiceClient())
    using (var stream = new MemoryStream(data))
    {
        var uploadRequestInfo = new RemoteFileInfo();
        uploadRequestInfo.FileName = guid.ToString();
        uploadRequestInfo.Length = data.Length;
        uploadRequestInfo.FileByteStream = stream;
        transferService.UploadImage(uploadRequestInfo);
    }
}

private byte[] DownloadImage(Guid guid)
{
    using (var transferService = new TransferServiceClient())
    {
        try
        {
            var request = new DownloadRequest(guid.ToString());
            var iconFile = transferService.DownloadImage(request);
            var data = ByteArrayOperations.FromStream(iconFile.FileByteStream);
            return data;
        }
        catch (Exception)
        {
            return null;
        }
    }
}

最后是客户端 app.config:

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

  <configSections>      

  <system.web>
    <httpRuntime maxRequestLength="2097150"/>
  </system.web>

  <system.serviceModel>
    <bindings>
      <basicHttpBinding>           
        <binding name="BasicHttpBinding_ITransferService" 
                 closeTimeout="04:01:00"
                 openTimeout="04:01:00" 
                 receiveTimeout="04:10:00" 
                 sendTimeout="04:01:00"
                 allowCookies="false" 
                 bypassProxyOnLocal="false"
                 hostNameComparisonMode="StrongWildcard"
                 maxBufferSize="2147483647" 
                 maxBufferPoolSize="2147483647"
                 maxReceivedMessageSize="2147483647"
                 messageEncoding="Text" 
                 textEncoding="utf-8"
                 transferMode="Streamed"
                 useDefaultWebProxy="true">
          <readerQuotas maxDepth="128"
                        maxStringContentLength="2147483647" 
                        maxArrayLength="2147483647"
                        maxBytesPerRead="2147483647" 
                        maxNameTableCharCount="2147483647" />
          <security mode="None">
            <transport clientCredentialType="None"
                    proxyCredentialType="None" realm="" />
            <message clientCredentialType="UserName" algorithmSuite="Default" />
          </security>
        </binding>
      </basicHttpBinding>
    </bindings>
    <client>

      <endpoint address="xxx/TransferService.svc"
                binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding_ITransferService"
                contract="Transfer.ITransferService" name="BasicHttpBinding_ITransferService" />
    </client>
  </system.serviceModel>
</configuration>

请注意，出于绝望，我添加了此部分:

<system.web>
  <httpRuntime maxRequestLength="2097150"/>
</system.web>

没有任何效果。

在错误日志中，启动服务后直接抛出了一个异常。我既不知道这意味着什么，也不知道它是否与问题有关:

System.ServiceModel.ProtocolException

Content Type multipart/related; type="application/xop+xml";start="<http://tempuri.org/0&gt;";boundary="uuid:b230e809-500b-4217-a08e-32ff49e13bac+id=5";start-info="text/xml" was sent to a service expecting text/xml; charset=utf-8. The client and service bindings may be mismatched.

我花了几天时间让它发挥作用，但真的不知道我还能尝试什么。如果有人可以查看配置并给出其他可以尝试的提示，我会非常非常高兴。所以，问题是:

传输失败的原因可能是什么？我该如何解决这个问题？

我也很乐意提供进一步的建议

如果根据问题中提供的信息无法识别问题的根源，该怎么办？

附录:我认为客户端异常没有任何用处，但我想将其包含在问题中，以便其他有相同问题的人更容易找到答案(希望如此):

A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll

Additional information: An existing connection was forcibly closed by the remote host

Answer 1

我没有看到服务配置文件中指定服务绑定(bind)的位置。我怀疑配置值没有被读取，这就是原因。

因此，我建议将服务配置文件中的绑定(bind)名称指定为 BasicHttpBinding_ITransferService(与客户端配置中使用的名称相同)，然后在 system.serviceModel 下添加以下内容 code>配置文件节点:

<services>
  <service name="TransferService" >
    <endpoint 
        binding="basicHttpBinding"
        bindingConfiguration="BasicHttpBinding_ITransferService"
        contract="Transfer.ITransferService" />
  </service>
</services>