Question

我有一个返回流对象的WCF服务。但由于某种原因，我得到了一个损坏的zip文件，我正在流媒体。所有代码都在下面请告知

合同代码

[ServiceContract(Namespace = "http://schemas.acme.it/2009/04/01")]
public interface IFileTransferService
{
    [OperationContract(IsOneWay = false)]
    FileDownloadReturnMessage DownloadFile(FileDownloadMessage request);

    [OperationContract()]
    string HellowWorld(string name);

}

[MessageContract]
public class FileDownloadMessage
{
    [MessageHeader(MustUnderstand = true)]
    public FileMetaData FileMetaData;
}

[MessageContract]
public class FileDownloadReturnMessage
{
    public FileDownloadReturnMessage(FileMetaData metaData, Stream stream)
    {
        this.DownloadedFileMetadata = metaData;
        this.FileByteStream = stream;
    }

    [MessageHeader(MustUnderstand = true)]
    public FileMetaData DownloadedFileMetadata;
    [MessageBodyMember(Order = 1)]
    public Stream FileByteStream;
}


[DataContract(Namespace = "http://schemas.acme.it/2009/04/01")]
public class FileMetaData
{
    public FileMetaData(string [] productIDs, string authenticationKey)
    {
        this.ids = productIDs;
     this.authenticationKey= authenticationKey;
    }

    [DataMember(Name = "ProductIDsArray", Order = 1, IsRequired = true)]
    public string[] ids;
    [DataMember(Name = "AuthenticationKey", Order = 2, IsRequired = true)]
    public string authenticationKey;
}

SVC文件代码

public class DownloadCoverScan : IFileTransferService
{
    public FileDownloadReturnMessage DownloadFile(FileDownloadMessage request)
    {
        FileStream stream = new FileStream(@"C:\Pictures.zip", FileMode.Open,
                                           FileAccess.Read);
        FileMetaData metaData= new FileMetaData(new string[] { "1", "2" },"asd");
        FileDownloadReturnMessage returnMessage =
            new FileDownloadReturnMessage(metaData,stream);
        return returnMessage;
    }
    public string HellowWorld(string name)
    {
        return "Hello " + name;
    }

}

配置代码

<system.serviceModel>
<behaviors>
  <serviceBehaviors>
    <behavior name="DownloadCoverScanBehavior">
      <serviceMetadata httpGetEnabled="true"/>
      <serviceDebug includeExceptionDetailInFaults="true" httpHelpPageEnabled="true" />
      <dataContractSerializer maxItemsInObjectGraph="2147483647"/>
    </behavior>
  </serviceBehaviors>
</behaviors>
<services>
  <service behaviorConfiguration="DownloadCoverScanBehavior" name="DownloadService.DownloadCoverScan">
    <endpoint address="" name="basicHttpStream" binding="basicHttpBinding" bindingConfiguration="httpLargeMessageStream"
              contract="DownloadService.IFileTransferService" />
  </service>
</services>
<bindings>
  <basicHttpBinding>
    <binding name="httpLargeMessageStream" maxReceivedMessageSize="2147483647" transferMode="Streamed"  messageEncoding="Mtom" />
  </basicHttpBinding>
</bindings>
</system.serviceModel>

客户代码

FileMetaData metaData = new FileMetaData();
metaData.ProductIDsArray = new string[] { "1", "2" };
metaData.AuthenticationKey = "test";
FileDownloadMessage inputParam = new FileDownloadMessage(metaData);
FileTransferServiceClient obj = new FileTransferServiceClient();
FileDownloadReturnMessage outputMessage = obj.DownloadFile(inputParam);
Byte[] buffer = new Byte[8192];
int byteRead = outputMessage.FileByteStream.Read(buffer, 0, buffer.Length);
Response.Buffer = false;
Response.ContentType = "application/zip";
Response.AppendHeader("content-length", buffer.Length.ToString());
Response.AddHeader("Content-disposition", "attachment; filename=testFile.zip");
Stream outStream = Response.OutputStream;
while (byteRead > 0)
{
    outStream.Write(buffer, 0, byteRead);
    byteRead = outputMessage.FileByteStream.Read(buffer, 0, buffer.Length);
}
outputMessage.FileByteStream.Close();
outStream.Close();

Answer 1

我认为问题可能是来自响应的Content-Length标头。您将其设置为8192，而实际上您还不知道长度。

但是，我并不完全确定。也许在此过程的早期出现问题。也许您可以在客户端代码中添加一些日志记录语句，以确保实际将所有字节写入输出流（例如，通过记录byteRead）。

Answer 2

这可能与您在服务器端关闭流的方式有关。我有一个类似于此的项目，其中客户端在异步调用中将流传递到服务器，并且.zip文件有时被破坏。事实证明，我没有正确关闭客户端的流，导致流不完整。

我没有看到显示服务关闭它在服务端发送的流的代码。

我认为除非关闭，否则流将无法正常完成。当没有任何东西要发送时，你仍然可以读取0个字节...

流式传输wcf服务返回损坏的流式文件

2 个答案: