VB.NET MessageQueue.Receive方法代碼示例

' 導入命名空間
Imports System.Messaging

    ' This class represents an object the following example 
    ' sends to a queue and receives from a queue.
    Public Class Order
        Public orderId As Integer
        Public orderTime As DateTime
    End Class


   
    Public Class MyNewQueue


        '
        ' Provides an entry point into the application.
        '		 
        ' This example sends and receives a message from
        ' a qeue.
        '

        Public Shared Sub Main()

            ' Create a new instance of the class.
            Dim myNewQueue As New MyNewQueue()

            ' Send a message to a queue.
            myNewQueue.SendMessage()

            ' Receive a message from a queue.
            myNewQueue.ReceiveMessage()

            Return

        End Sub


        '
        ' Sends an Order to a queue.
        '

        Public Sub SendMessage()

            ' Create a new order and set values.
            Dim sentOrder As New Order()
            sentOrder.orderId = 3
            sentOrder.orderTime = DateTime.Now

            ' Connect to a queue on the local computer.
            Dim myQueue As New MessageQueue(".\myQueue")

            ' Send the Order to the queue.
            myQueue.Send(sentOrder)

            Return

        End Sub


        '
        ' Receives a message containing an Order.
        '

        Public Sub ReceiveMessage()

            ' Connect to the a queue on the local computer.
            Dim myQueue As New MessageQueue(".\myQueue")

            ' Set the formatter to indicate the body contains an Order.
            myQueue.Formatter = New XmlMessageFormatter(New Type() _
                {GetType(Order)})

            Try

                ' Receive and format the message. 
                Dim myMessage As Message = myQueue.Receive()
                Dim myOrder As Order = CType(myMessage.Body, Order)

                ' Display message information.
                Console.WriteLine(("Order ID: " + _
                    myOrder.orderId.ToString()))
                Console.WriteLine(("Sent: " + _
                    myOrder.orderTime.ToString()))

            Catch m As MessageQueueException
                ' Handle Message Queuing exceptions.

            Catch e As InvalidOperationException
                ' Handle invalid serialization format.
                Console.WriteLine(e.Message)


                ' Catch other exceptions as necessary.

            End Try

            Return

        End Sub

End Class

' 導入命名空間
Imports System.Messaging

Public Class MyNewQueue


        '
        ' Provides an entry point into the application.
        ' 
        ' This example sends and receives a message from
        ' a transactional queue.
        '

        Public Shared Sub Main()

            ' Create a new instance of the class.
            Dim myNewQueue As New MyNewQueue

            ' Send a message to a queue.
            myNewQueue.SendMessageTransactional()

            ' Receive a message from a queue.
            myNewQueue.ReceiveMessageTransactional()

            Return

        End Sub


        '
        ' Sends a message to a queue.
        '

        Public Sub SendMessageTransactional()

            ' Connect to a queue on the local computer.
            Dim myQueue As New MessageQueue(".\myTransactionalQueue")

            ' Send a message to the queue.
            If myQueue.Transactional = True Then

                ' Create a transaction.
                Dim myTransaction As New MessageQueueTransaction

                ' Begin the transaction.
                myTransaction.Begin()

                ' Send the message.
                myQueue.Send("My Message Data.", myTransaction)

                ' Commit the transaction.
                myTransaction.Commit()

            End If

            Return

        End Sub


        '
        ' Receives a message containing an Order.
        '

        Public Sub ReceiveMessageTransactional()

            ' Connect to a transactional queue on the local computer.
            Dim myQueue As New MessageQueue(".\myTransactionalQueue")

            ' Set the formatter.
            myQueue.Formatter = New XmlMessageFormatter(New Type() _
                {GetType([String])})

            ' Create a transaction.
            Dim myTransaction As New MessageQueueTransaction

            Try

                ' Begin the transaction.
                myTransaction.Begin()

                ' Receive the message. 
                Dim myMessage As Message = _
                    myQueue.Receive(myTransaction)
                Dim myOrder As [String] = CType(myMessage.Body, _
                    [String])

                ' Display message information.
                Console.WriteLine(myOrder)

                ' Commit the transaction.
                myTransaction.Commit()


            Catch e As MessageQueueException

                ' Handle nontransactional queues.
                If e.MessageQueueErrorCode = _
                    MessageQueueErrorCode.TransactionUsage Then

                    Console.WriteLine("Queue is not transactional.")

                End If

                ' Else catch other sources of a MessageQueueException.


                ' Roll back the transaction.
                myTransaction.Abort()


                ' Catch other exceptions as necessary, such as 
                ' InvalidOperationException, thrown when the formatter
                ' cannot deserialize the message.

            End Try

            Return

        End Sub

End Class

' 導入命名空間
Imports System.Messaging

' This class represents an object the following example 
' receives from a queue.
Public Class Order
        Public orderId As Integer
        Public orderTime As DateTime
End Class


   
Public Class MyNewQueue


        '
        ' Provides an entry point into the application.
        '		 
        ' This example receives a message from a queue.
        '

        Public Shared Sub Main()

            ' Create a new instance of the class.
            Dim myNewQueue As New MyNewQueue()

            ' Receive a message from a queue.
            myNewQueue.ReceiveMessage()

            Return

        End Sub


        '
        ' Receives a message containing an Order.
        '

        Public Sub ReceiveMessage()

            ' Connect to the a queue on the local computer.
            Dim myQueue As New MessageQueue(".\myQueue")

            ' Set the formatter to indicate body contains an Order.
            myQueue.Formatter = New XmlMessageFormatter(New Type() _
                {GetType(Order)})

            Try

                ' Receive and format the message. 
                ' Wait 5 seconds for a message to arrive.
                Dim myMessage As Message = myQueue.Receive(New _
                    TimeSpan(0, 0, 5))
                Dim myOrder As Order = CType(myMessage.Body, Order)

                ' Display message information.
                Console.WriteLine(("Order ID: " + _
                    myOrder.orderId.ToString()))
                Console.WriteLine(("Sent: " + _
                    myOrder.orderTime.ToString()))

            Catch e As MessageQueueException
                ' Handle no message arriving in the queue.
                If e.MessageQueueErrorCode = _
                    MessageQueueErrorCode.IOTimeout Then

                    Console.WriteLine("No message arrived in queue.")

                End If

                ' Handle other sources of a MessageQueueException.

            Catch e As InvalidOperationException
                ' Handle invalid serialization format.
                Console.WriteLine(e.Message)

                ' Catch other exceptions as necessary.

            End Try

            Return

        End Sub

End Class

' 導入命名空間
Imports System.Messaging

Namespace MyProj


   
    Public Class MyNewQueue


        '**************************************************
        ' Provides an entry point into the application.
        ' 
        ' This example sends and receives a message from
        ' a transactional queue.
        '**************************************************

        Public Shared Sub Main()

            ' Create a new instance of the class.
            Dim myNewQueue As New MyNewQueue

            ' Send a message to a queue.
            myNewQueue.SendMessageTransactional()

            ' Receive a message from a queue.
            myNewQueue.ReceiveMessageTransactional()

            Return

        End Sub


        '**************************************************
        ' Sends a message to a transactional queue.
        '**************************************************

        Public Sub SendMessageTransactional()

            ' Connect to a queue on the local computer.
            Dim myQueue As New MessageQueue(".\myTransactionalQueue")

            ' Send a message to the queue.
            If myQueue.Transactional = True Then

                ' Create a transaction.
                Dim myTransaction As New MessageQueueTransaction

                ' Begin the transaction.
                myTransaction.Begin()

                ' Send the message.
                myQueue.Send("My Message Data.", myTransaction)

                ' Commit the transaction.
                myTransaction.Commit()

            End If

            Return

        End Sub


        '**************************************************
        ' Receives a message from the transactional queue.
        '**************************************************

        Public Sub ReceiveMessageTransactional()

            ' Connect to a transactional queue on the local computer.
            Dim myQueue As New MessageQueue(".\myTransactionalQueue")

            ' Set the formatter.
            myQueue.Formatter = New XmlMessageFormatter(New Type() _
                {GetType([String])})

            ' Create a transaction.
            Dim myTransaction As New MessageQueueTransaction

            Try

                ' Begin the transaction.
                myTransaction.Begin()

                ' Receive the message. 
                ' Wait five seconds for a message to arrive. 
                Dim myMessage As Message = myQueue.Receive(New _
                    TimeSpan(0, 0, 5), myTransaction)
                Dim myOrder As [String] = CType(myMessage.Body, _
                    [String])

                ' Display message information.
                Console.WriteLine(myOrder)

                ' Commit the transaction.
                myTransaction.Commit()


            Catch e As MessageQueueException

                ' Handle nontransactional queues.
                If e.MessageQueueErrorCode = _
                    MessageQueueErrorCode.TransactionUsage Then

                    Console.WriteLine("Queue is not transactional.")

                Else
                    ' Handle no message arriving in the queue.
                    If e.MessageQueueErrorCode = _
                        MessageQueueErrorCode.IOTimeout Then

                        Console.WriteLine("No message in queue.")

                    End If
                End If

                ' Else catch other sources of a MessageQueueException.

                ' Roll back the transaction.
                myTransaction.Abort()


                ' Catch other exceptions as necessary, such as InvalidOperationException,
                ' thrown when the formatter cannot deserialize the message.

            End Try

            Return

        End Sub

    End Class
End Namespace 'MyProj

' 導入命名空間
Imports System
Imports System.IO
Imports System.Messaging

Public Class MainClass
    
    Shared Sub Main()
        Dim mQ As MessageQueue
        Dim mes As Message
        Dim X As String
        Dim br As BinaryReader

        If MessageQueue.Exists(".\Private$\HelloWorld") Then
            mQ = New MessageQueue(".\Private$\HelloWorld")
        Else
            Console.WriteLine("Queue doesn't exist.")
            Return
        End If

        Try
            mes = mQ.Receive(New TimeSpan(0, 0, 3))
            br = New BinaryReader(mes.BodyStream)
            X = New String(br.ReadChars(CType(mes.BodyStream.Length, Integer)))
            Console.WriteLine("Received Message: {0}", X)
        Catch
            Console.WriteLine("No Message to Receive.")
        End Try
    End Sub
End Class