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MessageQueue.Receive Method

Receives the first message in the queue, removing it from the queue.

Overload List

Receives the first message available in the queue referenced by the MessageQueue. This call is synchronous, and blocks the current thread of execution until a message is available.

[Visual Basic] Overloads Public Function Receive() As Message
[C#] public Message Receive();
[C++] public: Message* Receive();
[JScript] public function Receive() : Message;

Receives the first message available in the transactional queue referenced by the MessageQueue. This call is synchronous, and blocks the current thread of execution until a message is available.

[Visual Basic] Overloads Public Function Receive(MessageQueueTransaction) As Message
[C#] public Message Receive(MessageQueueTransaction);
[C++] public: Message* Receive(MessageQueueTransaction*);
[JScript] public function Receive(MessageQueueTransaction) : Message;

Receives the first message available in the queue referenced by the MessageQueue. This call is synchronous, and blocks the current thread of execution until a message is available.

[Visual Basic] Overloads Public Function Receive(MessageQueueTransactionType) As Message
[C#] public Message Receive(MessageQueueTransactionType);
[C++] public: Message* Receive(MessageQueueTransactionType);
[JScript] public function Receive(MessageQueueTransactionType) : Message;

Receives the first message available in the queue referenced by the MessageQueue and waits until either a message is available in the queue, or the time-out expires.

[Visual Basic] Overloads Public Function Receive(TimeSpan) As Message
[C#] public Message Receive(TimeSpan);
[C++] public: Message* Receive(TimeSpan);
[JScript] public function Receive(TimeSpan) : Message;

Receives the first message available in the transactional queue referenced by the MessageQueue and waits until either a message is available in the queue, or the time-out expires.

[Visual Basic] Overloads Public Function Receive(TimeSpan, MessageQueueTransaction) As Message
[C#] public Message Receive(TimeSpan, MessageQueueTransaction);
[C++] public: Message* Receive(TimeSpan, MessageQueueTransaction*);
[JScript] public function Receive(TimeSpan, MessageQueueTransaction) : Message;

Receives the first message available in the queue referenced by the MessageQueue. This call is synchronous, and waits until either a message is available in the queue, or the time-out expires.

[Visual Basic] Overloads Public Function Receive(TimeSpan, MessageQueueTransactionType) As Message
[C#] public Message Receive(TimeSpan, MessageQueueTransactionType);
[C++] public: Message* Receive(TimeSpan, MessageQueueTransactionType);
[JScript] public function Receive(TimeSpan, MessageQueueTransactionType) : Message;

Example

[Visual Basic, C#, C++] Note   This example shows how to use one of the overloaded versions of Receive. For other examples that might be available, see the individual overload topics.
[Visual Basic] 
Imports System
Imports System.Messaging

Namespace MyProject


    '/ <summary>
    '/ Provides a container class for the example.
    '/ </summary>
    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 'Main


        '**************************************************
        ' 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

                myQueue.Send("My Message Data.", New _
                    MessageQueueTransaction())

            End If

            Return

        End Sub 'SendMessageTransactional


        '**************************************************
        ' 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 'ReceiveMessageTransactional

    End Class 'MyNewQueue
End Namespace 'MyProject

[C#] 
using System;
using System.Messaging;

namespace MyProject
{

    /// <summary>
    /// Provides a container class for the example.
    /// </summary>
    public class MyNewQueue
    {

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

        public static void Main()
        {
            // Create a new instance of the class.
            MyNewQueue myNewQueue = new MyNewQueue();

            // Send a message to a queue.
            myNewQueue.SendMessageTransactional();

            // Receive a message from a queue.
            myNewQueue.ReceiveMessageTransactional();

            return;
        }


        //**************************************************
        // Sends a message to a transactional queue.
        //**************************************************
        
        public void SendMessageTransactional()
        {
                        
            // Connect to a queue on the local computer.
            MessageQueue myQueue = new 
                MessageQueue(".\\myTransactionalQueue");

            // Send a message to the queue.
            if (myQueue.Transactional == true)
            {
                myQueue.Send("My Message Data.", new 
                    MessageQueueTransaction());
            }

            return;
        }


        //**************************************************
        // Receives a message from the transactional queue.
        //**************************************************
        
        public  void ReceiveMessageTransactional()
        {
            // Connect to a transactional queue on the local computer.
            MessageQueue myQueue = new 
                MessageQueue(".\\myTransactionalQueue");

            // Set the formatter.
            myQueue.Formatter = new XmlMessageFormatter(new Type[]
                {typeof(String)});
            
            // Create a transaction.
            MessageQueueTransaction myTransaction = new 
                MessageQueueTransaction();

            try
            {
                // Begin the transaction.
                myTransaction.Begin();
                
                // Receive the message. 
                // Wait five seconds for a message to arrive. 
                Message myMessage =    myQueue.Receive(new 
                    TimeSpan(0,0,5), myTransaction); 
                
                String myOrder = (String)myMessage.Body;

                // Display message information.
                Console.WriteLine(myOrder);

                // Commit the transaction.
                myTransaction.Commit();

            }
            
            catch (MessageQueueException e)
            {
                // Handle nontransactional queues.
                if (e.MessageQueueErrorCode == 
                    MessageQueueErrorCode.TransactionUsage)
                { 
                    Console.WriteLine("Queue is not transactional.");
                }

                // Handle no message arriving in the queue.
                else if (e.MessageQueueErrorCode == 
                    MessageQueueErrorCode.IOTimeout)
                {
                    Console.WriteLine("No message in queue.");
                }
                
                // Else catch other sources of MessageQueueException.

                // Roll back the transaction.
                myTransaction.Abort();
            }

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

            return;
        }
    }
}

[C++] 
#using <mscorlib.dll>
#using <system.dll>
#using <system.messaging.dll>

using namespace System;
using namespace System::Messaging;

/// <summary>
/// Provides a container class for the example.
/// </summary>
__gc class MyNewQueue 
{
    //*************************************************
    // Sends a message to a transactional queue.
    //*************************************************
public:
    void SendMessageTransactional() 
    {
        // Connect to a queue on the local computer.
        MessageQueue* myQueue = new MessageQueue(S".\\myTransactionalQueue");

        // Send a message to the queue.
        if (myQueue->Transactional == true) 
        {
            myQueue->Send(S"My Message Data.", new MessageQueueTransaction());
        }

        return;
    }

    //*************************************************
    // Receives a message from the transactional queue.
    //*************************************************
public:
    void ReceiveMessageTransactional() 
    {
        // Connect to a transactional queue on the local computer.
        MessageQueue* myQueue = new MessageQueue(S".\\myTransactionalQueue");

        // Set the formatter.
        Type* p __gc[] = new Type* __gc[1];
        p[0] = __typeof(String);
        myQueue->Formatter = new XmlMessageFormatter( p );

        // Create a transaction.
        MessageQueueTransaction* myTransaction = new MessageQueueTransaction();

        try 
        {
            // Begin the transaction.
            myTransaction->Begin();

            // Receive the message. 
            // Wait five seconds for a message to arrive. 
            Message* myMessage = myQueue->Receive(TimeSpan(0, 0, 5), myTransaction); 

            String* myOrder = static_cast<String*>(myMessage->Body);

            // Display message information.
            Console::WriteLine(myOrder);

            // Commit the transaction.
            myTransaction->Commit();

        } 
        catch (MessageQueueException* e) 
        {
            // Handle nontransactional queues.
            if (e->MessageQueueErrorCode == 
                MessageQueueErrorCode::TransactionUsage) 
            { 
                Console::WriteLine(S"Queue is not transactional.");
            }

            // Handle no message arriving in the queue.
            else if (e->MessageQueueErrorCode == 
                MessageQueueErrorCode::IOTimeout) 
            {
                Console::WriteLine(S"No message in queue.");
            }

            // Else catch other sources of MessageQueueException.

            // Roll back the transaction.
            myTransaction->Abort();
        }

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

        return;
    }
};

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

int main() 
{
    // Create a new instance of the class.
    MyNewQueue* myNewQueue = new MyNewQueue();

    // Send a message to a queue.
    myNewQueue->SendMessageTransactional();

    // Receive a message from a queue.
    myNewQueue->ReceiveMessageTransactional();

    return 0;
}

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

See Also

MessageQueue Class | MessageQueue Members | System.Messaging Namespace

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