我的第一个问题是温柔的=）
以下是VS2010中的.Net 4，VB.Net。最终目标是通过Tcp绑定从客户端接收（完整）流到IIS托管WCF服务。我面临的问题是该服务无法从提供的流中读取任何字节。现在有了细节......为了简洁，我已经删除了相当数量但是，如果我省略了重要的东西，请告诉我。
服务合同如下：
<ServiceContract(Namespace:="ImageSystem")> _
Public Interface IUploadService
<OperationContract()> _
Function UploadFile(ByVal file As ImageUpload) As ImageUpload
End Interface
数据合约 ImageUpload 如下：
<MessageContract()> _
Public Class ImageUpload
#Region " Message Header "
Private _ImageID As Nullable(Of Long)
<MessageHeader()> _
Public Property ImageID() As Nullable(Of Long)
Get
Return _ImageID
End Get
Set(ByVal value As Nullable(Of Long))
_ImageID = value
End Set
End Property
'... a few other value type properties
#End Region
#Region " Message Body"
' Do not add any more members to the message body or streaming support will be disabled!
<MessageBodyMember()> _
Public Data As System.IO.Stream
#End Region
End Class
相关的服务器配置/绑定如下（这些显然只是开发环境设置）：
<system.serviceModel>
<bindings>
<netTcpBinding>
<binding name="netTcpStreamBinding" transferMode="Streamed" maxBufferSize="20971520" maxReceivedMessageSize="20971520"/>
</netTcpBinding>
</bindings>
<services>
<service behaviorConfiguration="UploadServiceBehaviour"
name="ImageSystem.SVC.UploadService">
<endpoint address="" binding="netTcpBinding" bindingConfiguration="netTcpStreamBinding"
contract="ImageSystem.SVC.IUploadService">
<identity>
<dns value="localhost" />
</identity>
</endpoint>
<endpoint address="mex" binding="mexTcpBinding" contract="IMetadataExchange" />
<host>
<baseAddresses>
<add baseAddress="net.tcp://localhost:809/UploadService" />
</baseAddresses>
</host>
</service>
</services>
<behaviors>
<serviceBehaviors>
<behavior name="UploadServiceBehaviour">
<serviceMetadata httpGetEnabled="false"/>
<serviceDebug includeExceptionDetailInFaults="true"/>
</behavior>
</serviceBehaviors>
</behaviors>
</system.serviceModel>
WCF服务是一个服务库，由Web应用程序托管。 Web应用程序项目在我的本地IIS 7.5中运行。 IIS已配置为启用TCP连接，并且应用程序池标识配置了对合同实现的相关权限。 VS2010以管理员身份运行，以便在IIS中启用调试。
为了测试合同实现，我将Windows控制台应用程序设置为（测试）客户端。通过在IIS主机（http：//localhost/ImageSystem/UploadService.svc）中向服务添加服务引用来生成客户端代理类。服务引用配置为生成异步方法。
相关的自动生成的客户端配置如下（请注意，我已尝试增加maxBufferPoolSize，maxBufferSize和maxReceivedMessageSize以匹配“20971520”的服务器配置，但无济于事）：
[编辑：reliableSessions部分根据Sixto Saez的建议进行评论但无效]
<system.serviceModel>
<bindings>
<binding name="NetTcpBinding_IUploadService" closeTimeout="00:01:00"
openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"
transactionFlow="false" transferMode="Streamed" transactionProtocol="OleTransactions"
hostNameComparisonMode="StrongWildcard" listenBacklog="10" maxBufferPoolSize="20971520"
maxBufferSize="20971520" maxConnections="10" maxReceivedMessageSize="20971520">
<readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
maxBytesPerRead="4096" maxNameTableCharCount="16384" />
<!--<reliableSession ordered="true" inactivityTimeout="00:10:00"
enabled="false" />-->
<security mode="None">
<transport clientCredentialType="Windows" protectionLevel="EncryptAndSign" />
<message clientCredentialType="Windows" />
</security>
</binding>
</netTcpBinding>
</bindings>
<client>
<endpoint address="net.tcp://mycomputername.mydomain/ImageSystem/UploadService.svc"
binding="netTcpBinding" bindingConfiguration="NetTcpBinding_IUploadService"
contract="UploadService.Local.IUploadService" name="NetTcpBinding_IUploadService">
<identity>
<dns value="localhost" />
</identity>
</endpoint>
</client>
</system.serviceModel>
客户端使用情况如下：
Public Sub Test()
Dim serviceClient As UploadService.Local.UploadServiceClient = New UploadService.Local.UploadServiceClient
AddHandler serviceClient.UploadFileCompleted, AddressOf LocalTestCallback
Dim ms As MemoryStream = New MemoryStream
My.Resources.Penguins.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg)
serviceClient.ClientCredentials.Windows.ClientCredential.Domain = "MYDOMAIN"
serviceClient.ClientCredentials.Windows.ClientCredential.UserName = "User"
serviceClient.ClientCredentials.Windows.ClientCredential.Domain = "Password123"
serviceClient.UploadFileAsync(Nothing, ..., ms, ms) '"..." is obviously not actually here, other values omitted. "ms" is passed as UserState object in addition to fulfilling the 'Data' parameter
End Sub
如果您想知道（或重要），企鹅图像是样本图片目录中随Windows 7提供的图像。图像为777,835字节（应在相关的请求/缓冲区最大大小范围内）。
我尝试了两种在服务器端读取图像的方法。
方法1：
Public Function UploadFile(ByVal file As ImageUpload) As ImageUpload Implements IUploadService.UploadFile
Dim uploadBuffer(Helper.Settings.AppSettings(Of Integer)("UploadBufferSize", True) - 1) As Byte
Dim ms As MemoryStream = New MemoryStream()
Dim bytesRead As Integer
Do
bytesRead = file.Data.Read(uploadBuffer, 0, uploadBuffer.Length)
ms.Write(uploadBuffer, 0, bytesRead)
Loop Until bytesRead = 0
End Function
方法2：
Public Function UploadFile(ByVal file As ImageUpload) As ImageUpload Implements IUploadService.UploadFile
Dim reader As StreamReader = New StreamReader(file.Data)
Dim imageB64 As String = reader.ReadToEnd
ms = New MemoryStream(Convert.FromBase64String(imageB64))
End Function
在这两种情况下，ms.Length = 0.更明显，在第二种方法中，imageB64 =“”（空字符串）。
为什么我不从流中收到任何内容？另外，作为一个偷偷摸摸的子问题，为什么生成的代理类不提供接受 ImageUpload 类型的对象的重载？
提前谢谢!!
答案 0 :(得分：2)
对我来说，你会遇到你提到的问题似乎很奇怪，所以我很好奇并使用你的服务合同整理了一个实现。那个实际上是直接工作的。我实际上并不知道你的情况出了什么问题（这不是很明显），但我想在这里发布一个有效的解决方案，希望这能帮助你解决问题。
不幸的是，由于我多年前放弃了VB，我只能提供C＃代码。希望没关系。
服务器Web.config（在IIS中测试，使用net.tcp绑定）：
<system.serviceModel>
<bindings>
<netTcpBinding>
<binding transferMode="Streamed" maxReceivedMessageSize="1000000">
<security mode="None"/>
</binding>
</netTcpBinding>
</bindings>
<services>
<service name="ImageSystem.SVC.UploadService">
<endpoint address="" binding="netTcpBinding" contract="ImageSystem.SVC.IUploadService">
</endpoint>
<endpoint address="mex" kind="mexEndpoint" binding="mexTcpBinding"/>
</service>
</services>
<behaviors>
<serviceBehaviors>
<behavior>
<serviceMetadata httpGetEnabled="false"/>
<serviceDebug includeExceptionDetailInFaults="true"/>
</behavior>
</serviceBehaviors>
</behaviors>
</system.serviceModel>
客户端app.config（控制台测试应用）：
<system.serviceModel>
<bindings>
<netTcpBinding>
<binding transferMode="Streamed" maxReceivedMessageSize="1000000">
<security mode="None"/>
</binding>
</netTcpBinding>
</bindings>
<client>
<endpoint
address="net.tcp://localhost/WcfService1/UploadService.svc"
binding="netTcpBinding"
contract="ImageServices.IUploadService"
name="NetTcpBinding_IUploadService">
</endpoint>
</client>
</system.serviceModel>
服务合同＆amp;实施
[ServiceContract(Namespace="urn:ImageSystem")]
public interface IUploadService
{
[OperationContract]
ImageUpload UploadFile(ImageUpload file);
}
[MessageContract]
public class ImageUpload
{
[MessageHeader]
public long? ImageID { get; set; }
[MessageBodyMember]
public Stream Data;
}
public class UploadService : IUploadService
{
public ImageUpload UploadFile(ImageUpload file)
{
long length;
using (var ms = new MemoryStream())
{
file.Data.CopyTo(ms);
length = ms.Length;
}
return new ImageUpload { ImageID = length, Data = new MemoryStream() };
}
}
测试应用：
private static readonly string imgPath = @"C:\Pictures\somepicture.jpg";
private static readonly EventWaitHandle waitHandle = new AutoResetEvent(false);
static void Main()
{
long? result;
using (var service = new ImageServices.UploadServiceClient("NetTcpBinding_IUploadService"))
{
var image = new ImageServices.ImageUpload();
using (var imgStream = File.OpenRead(imgPath))
{
image.Data = imgStream;
service.UploadFileCompleted += (sender, e) =>
{
result = e.Result;
if (e.Data != null) image.Data.Dispose();
waitHandle.Set();
};
service.UploadFileAsync(null, imgStream);
waitHandle.WaitOne();
}
}
}
首先，正如您所看到的，配置文件可以更简单。特别是大BufferSize值不是必需的。然后，关于服务合同，我不清楚为什么Upload操作会收到并返回ImageUpload消息。在我的实现中，我正在返回ImageID参数中的上传文件大小，当然只是为了演示目的。我不知道你的合同背后的原因是什么，以及你真正希望返回的是什么。
实际上，当我知道为什么你的代码可能失败时，正要点击“发送”。在测试客户端中，在致电serviceClient.UploadFileAsync()之前，请将此行添加到您的代码中：ms.Seek(0, SeekOrigin.Begin)。
这会将MemoryStream的位置重置回其开头。如果你不这样做，MemoryStream只会从当前位置消耗，这是它的结束 - 这解释了服务端收到的流的长度= 0！
答案 1 :(得分：0)
您可能已经seen the information in this MSDN article但是您应该查看名为Streaming Data的部分及其列出的限制。您的客户端配置显示将ordered属性设置为“true”的reliableSession元素，该流不支持流式传输。
我不知道这是否是您问题的具体原因，但这是一个开始。该文章还很好地布局了流媒体所需的基本配置，因此您应该确保您的配置符合其建议。