Imports System.ServiceModel
Imports System.ServiceModel.Channels
Imports System.ServiceModel.Dispatcher
Imports System.ServiceModel.Description
Imports System.ComponentModel
Public Class HttpUserAgentMessageInspector

    Implements IClientMessageInspector
    Private Const USER_AGENT_HTTP_HEADER As String = "user-agent"

    Private m_userAgent As String

    Public Sub New(ByVal userAgent As String)
        Me.m_userAgent = userAgent
    End Sub

#Region "IClientMessageInspector Members"

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

    Public Function BeforeSendRequest(ByRef request As System.ServiceModel.Channels.Message, ByVal channel As System.ServiceModel.IClientChannel) As Object Implements IClientMessageInspector.BeforeSendRequest
        Dim httpRequestMessage As HttpRequestMessageProperty
        Dim httpRequestMessageObject As New Object
        If request.Properties.TryGetValue(HttpRequestMessageProperty.Name, httpRequestMessageObject) Then
            httpRequestMessage = TryCast(httpRequestMessageObject, HttpRequestMessageProperty)
            If String.IsNullOrEmpty(httpRequestMessage.Headers(USER_AGENT_HTTP_HEADER)) Then
                httpRequestMessage.Headers(USER_AGENT_HTTP_HEADER) = Me.m_userAgent
            End If
        Else
            httpRequestMessage = New HttpRequestMessageProperty()
            httpRequestMessage.Headers.Add(USER_AGENT_HTTP_HEADER, Me.m_userAgent)
            request.Properties.Add(HttpRequestMessageProperty.Name, httpRequestMessage)
        End If
        Return Nothing
    End Function

#End Region
End Class
Public Class HttpUserAgentEndpointBehavior
    Implements IEndpointBehavior
    Private m_userAgent As String

    Public Sub New(ByVal userAgent As String)
        Me.m_userAgent = userAgent
    End Sub

#Region "IEndpointBehavior Members"

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

    Public Sub ApplyClientBehavior(ByVal endpoint As ServiceEndpoint, ByVal clientRuntime As System.ServiceModel.Dispatcher.ClientRuntime) Implements IEndpointBehavior.ApplyClientBehavior
        Dim inspector As New HttpUserAgentMessageInspector(Me.m_userAgent)
        clientRuntime.ClientMessageInspectors.Add(inspector)
    End Sub

    Public Sub ApplyDispatchBehavior(ByVal endpoint As ServiceEndpoint, ByVal endpointDispatcher As System.ServiceModel.Dispatcher.EndpointDispatcher) Implements IEndpointBehavior.ApplyDispatchBehavior
    End Sub

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

#End Region
End Class