如何访问用于在WCF服务（服务器端）上实现IDispatchMessageInspector的类中的属性？

Question

我正在使用WCF IClientMessageInspector将标头中的信息发送到WCF服务（wsHTTP）。我正在使用IDispatchMessageInspector接收信息并填充String属性。

我验证了标头正在正确发送信息，因为我在我的特定方法中使用了FindHeader，但我宁愿只访问具有Token属性的自定义类并从那里获取Token，而不是在一个中执行FindHeader。所有其他方法调用以获取标头值的单独方法。

所以我的问题是，从服务器端（我假设的OperationContext）如何访问这个具有用标题信息填充的Token属性的类实例？

以下是整个班级的代码：

地区“IMPORTS”

Imports System.ServiceModel
Imports System.ServiceModel.Dispatcher
Imports System.ServiceModel.Description
Imports System.ServiceModel.Channels
Imports System.ServiceModel.Configuration

结束地区

Public Class MessageInspector
    Inherits BehaviorExtensionElement
    Implements IClientMessageInspector, IDispatchMessageInspector, IEndpointBehavior

    Private Const headerName As String = "HeaderToken"
    Private Const headerNamespace As String = "urn:com.nc-software.services:v1"

    Private _token As String
    Public Property Token() As String
        Get
            Return _token
        End Get
        Set(ByVal Value As String)
            _token = Value
        End Set
    End Property

    Public Overrides ReadOnly Property BehaviorType() As System.Type
        Get
            Return GetType(MessageInspector)
        End Get
    End Property

    Protected Overrides Function CreateBehavior() As Object
        Return New MessageInspector
    End Function

区域“IEndpointBehavior”

Public Sub AddBindingParameters(ByVal endpoint As System.ServiceModel.Description.ServiceEndpoint, ByVal bindingParameters As System.ServiceModel.Channels.BindingParameterCollection) Implements System.ServiceModel.Description.IEndpointBehavior.AddBindingParameters
End Sub

Public Sub ApplyClientBehavior(ByVal endpoint As System.ServiceModel.Description.ServiceEndpoint, ByVal clientRuntime As System.ServiceModel.Dispatcher.ClientRuntime) Implements System.ServiceModel.Description.IEndpointBehavior.ApplyClientBehavior
    clientRuntime.MessageInspectors.Add(Me)
End Sub

Public Sub ApplyDispatchBehavior(ByVal endpoint As System.ServiceModel.Description.ServiceEndpoint, ByVal endpointDispatcher As System.ServiceModel.Dispatcher.EndpointDispatcher) Implements System.ServiceModel.Description.IEndpointBehavior.ApplyDispatchBehavior
    endpointDispatcher.DispatchRuntime.MessageInspectors.Add(Me)
End Sub

Public Sub Validate(ByVal endpoint As System.ServiceModel.Description.ServiceEndpoint) Implements System.ServiceModel.Description.IEndpointBehavior.Validate
End Sub

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区域“IClientMessageInspector”

Public Sub AfterReceiveReply(ByRef reply As System.ServiceModel.Channels.Message, ByVal correlationState As Object) Implements System.ServiceModel.Dispatcher.IClientMessageInspector.AfterReceiveReply
End Sub

Public Function BeforeSendRequest(ByRef request As System.ServiceModel.Channels.Message, ByVal channel As System.ServiceModel.IClientChannel) As Object Implements System.ServiceModel.Dispatcher.IClientMessageInspector.BeforeSendRequest
    Dim header As New MessageHeader(Of String)(Token)
    Dim untypedHeader As MessageHeader = header.GetUntypedHeader(headerName, headerNamespace)
    request.Headers.Add(untypedHeader)
    Return Nothing
End Function

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区域“IDispatchMessageInspector”

Public Function AfterReceiveRequest(ByRef request As System.ServiceModel.Channels.Message, ByVal channel As System.ServiceModel.IClientChannel, ByVal instanceContext As System.ServiceModel.InstanceContext) As Object Implements System.ServiceModel.Dispatcher.IDispatchMessageInspector.AfterReceiveRequest
    Try
        Dim headers As MessageHeaders = OperationContext.Current.IncomingMessageHeaders
        Dim headerIndex As Integer = headers.FindHeader(headerName, headerNamespace)
        If headerIndex >= 0 Then
            Token = headers.GetHeader(Of String)(headerIndex)
        End If
    Catch
    End Try
    Return Nothing
End Function

Public Sub BeforeSendReply(ByRef reply As System.ServiceModel.Channels.Message, ByVal correlationState As Object) Implements System.ServiceModel.Dispatcher.IDispatchMessageInspector.BeforeSendReply
End Sub

结束地区

结束班

Answer 1

根据模式，我看到WCF团队正在建立，我的建议是让你的IDispatchMessageInspector将标头的值移到当前的OperationContext的IncomingMessageProperties字典中。通过执行此操作，该值将绑定到当前操作上下文，并由WCF运行时为您执行所有执行阶段。

至于如何在堆栈中进一步读取该值，您可以做两件事。首先，您可以公开您将用于读取/写入静态只读字符串上的属性集合的值的字符串键，其他代码可以使用它来从OperationContext.Current本身检索值，如下所示：

int value = (int)OperationContext.Current.IncomingMessageProperties[MyMessageProperty.MyHeader];

现在，这仍然需要对所有需要阅读该值的人进行大量编码。获取当前上下文，使用键索引到字典中并将结果转换为正确的类型（我使用int作为上面的示例）。如果你想获得幻想，你可以采取的下一步是通过你自己的上下文类公开这些属性，这样人们就可以像普通的，强类型的CLR属性一样访问它们。这可能看起来像这样：

首先，在名为MyOperationContext的类上实现静态访问​​器属性：

public static int MyHeader
{
    get
    {
        return (int)OperationContext.Current.IncomingMessageProperties[MyMessageProperty.MyMessageProperty];
    }

    set
    {
        OperationContext.Current.IncomingMessageProperties[MyMessageProperty.MyMessageProperty] = value;
    }
}

现在，在您需要阅读此标题的各种实现中，他们只会这样做：

int value = MyOperationContext.MyHeader;