我有点卡住了...
我的目标非常简单:我想通过一个IIS托管(然后是Windows Azure)的WCF服务公开,通过该服务,我可以使用流式上传文件,并添加有关要上传的文件的一些元数据(文件名,MD5散列等常见信息...),并能够显示有关上传的准确进度信息。
首先,我创建了一个派生类StreamWithProgress,该类从FileStream继承,我已重写Read方法以引发每次读取时传递进度信息的事件。
其次,我使用MessageContract ( http://msdn.microsoft.com/en-us/library/ms730255.aspx ) 创建了一个WCF服务,将META数据和流对象包装到单个SOAP信封中。此服务非常简单,仅公开用于上传的单个方法。
我将所有缓冲区大小设置为接受大量数据,如下所示:
根据 httpRuntime 设置:
http://msdn.microsoft.com/en-us/library/e1f13641(v=vs.71).aspx 和
http://kjellsj.blogspot.com/2007/02/wcf-streaming-upload-files-over-http.html
根据以下内容设置IIS\ASP兼容性设置:
根据以下内容禁用批处理:
- http://msdn.microsoft.com/en-us/library/system.servicemodel.icontextchannel.allowoutputbatching.aspx
<?xml version="1.0"?>
<configuration>
<system.serviceModel>
<bindings>
<basicHttpBinding>
<binding name="uploadBasicHttpBinding"
maxReceivedMessageSize="2147483647"
transferMode="Streamed"
messageEncoding="Mtom"
maxBufferPoolSize="2147483647"
maxBufferSize="2147483647">
<readerQuotas maxArrayLength="2147483647"
maxBytesPerRead="2147483647"
maxDepth="2147483647"
maxNameTableCharCount="2147483647"
maxStringContentLength="2147483647"/>
</binding>
</basicHttpBinding>
</bindings>
<behaviors>
<serviceBehaviors>
<behavior name="defaultBehavior">
<serviceMetadata httpGetEnabled="true"/>
<serviceDebug includeExceptionDetailInFaults="false"/>
<dataContractSerializer maxItemsInObjectGraph="2147483647"/>
</behavior>
</serviceBehaviors>
</behaviors>
<!-- Add this for BufferOutput setting -->
<serviceHostingEnvironment multipleSiteBindingsEnabled="true" aspNetCompatibilityEnabled="true"/>
<services>
<service name="WcfService1.Service1" behaviorConfiguration="defaultBehavior">
<endpoint binding="basicHttpBinding" contract="WcfService1.IService1" bindingConfiguration="uploadBasicHttpBinding"/>
<endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/>
</service>
</services>
</system.serviceModel>
<system.webServer>
<modules runAllManagedModulesForAllRequests="true"/>
</system.webServer>
<system.web>
<compilation debug="true"/>
<httpRuntime maxRequestLength="2147483647" />
</system.web>
</configuration>
服务合同:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Text;
using System.IO;
namespace WcfService1
{
[ServiceContract]
public interface IService1
{
[OperationContract(IsOneWay=true)]
void UploadStream(Encapsulator data);
}
}
实际服务:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Text;
using System.IO;
using System.Web;
using System.ServiceModel.Activation;
namespace WcfService1
{
[MessageContract]
public class Encapsulator
{
[MessageHeader(MustUnderstand = true)]
public string fileName;
[MessageBodyMember(Order = 1)]
public Stream requestStream;
}
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
public class Service1 : IService1
{
public Service1()
{
HttpContext context = HttpContext.Current;
if (context != null)
{
context.Response.BufferOutput = false;
}
}
public void UploadStream(Encapsulator data)
{
const int BUFFER_SIZE = 1024;
int bytesRead = 0;
byte[] dataRead = new byte[BUFFER_SIZE];
string filePath = Path.Combine(@"C:\MiscTestFolder", data.fileName);
string logPath = Path.Combine(@"C:\MiscTestFolder", string.Concat(data.fileName, ".log"));
bytesRead = data.requestStream.Read(dataRead, 0, BUFFER_SIZE);
StreamWriter logStreamWriter = new StreamWriter(logPath);
using (System.IO.FileStream fileStream = new System.IO.FileStream(filePath, FileMode.Create))
{
while (bytesRead > 0)
{
fileStream.Write(dataRead, 0, bytesRead);
fileStream.Flush();
logStreamWriter.WriteLine("Flushed {0} bytes", bytesRead.ToString());
logStreamWriter.Flush();
bytesRead = data.requestStream.Read(dataRead, 0, BUFFER_SIZE);
}
fileStream.Close();
}
logStreamWriter.Close();
}
}
}
客户端 app.config:
<?xml version="1.0"?>
<configuration>
<system.serviceModel>
<bindings>
<basicHttpBinding>
<binding name="BasicHttpBinding_IService1" closeTimeout="00:01:00"
openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"
allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard"
maxBufferSize="65536" maxBufferPoolSize="524288" maxReceivedMessageSize="65536"
messageEncoding="Mtom" textEncoding="utf-8" transferMode="Streamed"
useDefaultWebProxy="true">
<readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
maxBytesPerRead="4096" maxNameTableCharCount="16384" />
<security mode="None">
<transport clientCredentialType="None" proxyCredentialType="None"
realm="" />
<message clientCredentialType="UserName" algorithmSuite="Default" />
</security>
</binding>
</basicHttpBinding>
</bindings>
<client>
<endpoint address="http://localhost/WcfService1/Service1.svc"
binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding_IService1"
contract="UploadService.IService1" name="BasicHttpBinding_IService1" />
</client>
</system.serviceModel>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
</startup>
</configuration>
客户端主要代码:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using CustomFileUploaderTester.UploadService;
using System.ServiceModel;
using System.IO;
namespace CustomFileUploaderTester
{
class Program
{
private static long bytesRead = 0;
static void Main(string[] args)
{
Service1Client client = new Service1Client();
using (StreamWithProgress fstream = new StreamWithProgress(@"C:\BladieBla\someFile.wmv", FileMode.Open))
{
client.InnerChannel.AllowOutputBatching = false;
fstream.ProgressChange += new EventHandler<StreamReadProgress>(fstream_ProgressChange);
client.UploadStream("someFile.wmv", fstream);
fstream.Close();
}
Console.ReadKey();
}
static void fstream_ProgressChange(object sender, StreamReadProgress e)
{
bytesRead += e.BytesRead;
Console.WriteLine(bytesRead.ToString());
}
}
}
派生的 FileStream 类(StreamWithProgress)
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
namespace CustomFileUploaderTester
{
public class StreamReadProgress : EventArgs
{
#region Public Properties
public long BytesRead
{
get;
set;
}
public long Length
{
get;
set;
}
#endregion
#region Constructor
public StreamReadProgress(long bytesRead, long fileLength)
: base()
{
this.BytesRead = bytesRead;
this.Length = fileLength;
}
#endregion
}
public sealed class StreamWithProgress : FileStream
{
#region Public Events
public event EventHandler<StreamReadProgress> ProgressChange;
#endregion
#region Constructor
public StreamWithProgress(string filePath, FileMode fileMode)
: base(filePath, fileMode)
{
}
#endregion
#region Overrides
public override int Read(byte[] array, int offset, int count)
{
int bytesRead = base.Read(array, offset, count);
this.RaiseProgressChanged(bytesRead);
return bytesRead;
}
#endregion
#region Private Worker Methods
private void RaiseProgressChanged(long bytesRead)
{
EventHandler<StreamReadProgress> progressChange = this.ProgressChange;
if (progressChange != null)
{
progressChange(this, new StreamReadProgress(bytesRead, this.Length));
}
}
#endregion
}
}
-- 更新:2012-04-20
在我安装了一个环回适配器之后,我使用RawCap跟踪了通信,并发现数据实际上是流式传输的,但是IIS服务器在调用Web方法之前会缓冲所有数据!
根据这篇文章:
http://social.msdn.microsoft.com/Forums/is/wcf/thread/cfe625b2-1890-471b-a4bd-94373daedd39
这是ASP.Net的行为,WCF继承了它...但他们正在讨论在.Net 4.5中修复这个问题 :|
如果有其他建议,将会很棒!
谢谢!