MessageQueue Classe

Definição

public ref class MessageQueue : System::ComponentModel::Component, System::Collections::IEnumerable

[System.ComponentModel.TypeConverter(typeof(System.Messaging.Design.MessageQueueConverter))]
public class MessageQueue : System.ComponentModel.Component, System.Collections.IEnumerable

[System.ComponentModel.TypeConverter(typeof(System.Messaging.Design.MessageQueueConverter))]
[System.Messaging.MessagingDescription("MessageQueueDesc")]
public class MessageQueue : System.ComponentModel.Component, System.Collections.IEnumerable

[<System.ComponentModel.TypeConverter(typeof(System.Messaging.Design.MessageQueueConverter))>]
type MessageQueue = class
    inherit Component
    interface IEnumerable

[<System.ComponentModel.TypeConverter(typeof(System.Messaging.Design.MessageQueueConverter))>]
[<System.Messaging.MessagingDescription("MessageQueueDesc")>]
type MessageQueue = class
    inherit Component
    interface IEnumerable

Public Class MessageQueue
Inherits Component
Implements IEnumerable

Herança

Object

MarshalByRefObject

Component

MessageQueue

Atributos

TypeConverterAttribute MessagingDescriptionAttribute

Implementações

IEnumerable

Exemplos

O exemplo de código seguinte cria novos MessageQueue objetos usando vários tipos de sintaxe de nomes de caminho. Em cada caso, envia uma mensagem para a fila cujo caminho está definido no construtor.

#using <system.dll>
#using <system.messaging.dll>

using namespace System;
using namespace System::Messaging;
ref class MyNewQueue
{
public:

   // References public queues.
   void SendPublic()
   {
      MessageQueue^ myQueue = gcnew MessageQueue( ".\\myQueue" );
      myQueue->Send( "Public queue by path name." );
      return;
   }


   // References private queues.
   void SendPrivate()
   {
      MessageQueue^ myQueue = gcnew MessageQueue( ".\\Private$\\myQueue" );
      myQueue->Send( "Private queue by path name." );
      return;
   }


   // References queues by label.
   void SendByLabel()
   {
      MessageQueue^ myQueue = gcnew MessageQueue( "Label:TheLabel" );
      myQueue->Send( "Queue by label." );
      return;
   }


   // References queues by format name.
   void SendByFormatName()
   {
      MessageQueue^ myQueue = gcnew MessageQueue( "FormatName:Public=5A5F7535-AE9A-41d4 -935C-845C2AFF7112" );
      myQueue->Send( "Queue by format name." );
      return;
   }


   // References computer journal queues.
   void MonitorComputerJournal()
   {
      MessageQueue^ computerJournal = gcnew MessageQueue( ".\\Journal$" );
      while ( true )
      {
         Message^ journalMessage = computerJournal->Receive();
         
         // Process the journal message.
      }
   }


   // References queue journal queues.
   void MonitorQueueJournal()
   {
      MessageQueue^ queueJournal = gcnew MessageQueue( ".\\myQueue\\Journal$" );
      while ( true )
      {
         Message^ journalMessage = queueJournal->Receive();
         
         // Process the journal message.
      }
   }


   // References dead-letter queues.
   void MonitorDeadLetter()
   {
      MessageQueue^ deadLetter = gcnew MessageQueue( ".\\DeadLetter$" );
      while ( true )
      {
         Message^ deadMessage = deadLetter->Receive();
         
         // Process the dead-letter message.
      }
   }


   // References transactional dead-letter queues.
   void MonitorTransactionalDeadLetter()
   {
      MessageQueue^ TxDeadLetter = gcnew MessageQueue( ".\\XactDeadLetter$" );
      while ( true )
      {
         Message^ txDeadLetter = TxDeadLetter->Receive();
         
         // Process the transactional dead-letter message.
      }
   }

};


//*************************************************
// Provides an entry point into the application.
//         
// This example demonstrates several ways to set
// a queue's path.
//*************************************************
int main()
{
   
   // Create a new instance of the class.
   MyNewQueue^ myNewQueue = gcnew MyNewQueue;
   myNewQueue->SendPublic();
   myNewQueue->SendPrivate();
   myNewQueue->SendByLabel();
   myNewQueue->SendByFormatName();
   myNewQueue->MonitorComputerJournal();
   myNewQueue->MonitorQueueJournal();
   myNewQueue->MonitorDeadLetter();
   myNewQueue->MonitorTransactionalDeadLetter();
   return 0;
}

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 demonstrates several ways to set
        // a queue's path.
        //**************************************************

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

            myNewQueue.SendPublic();
            myNewQueue.SendPrivate();
            myNewQueue.SendByLabel();
            myNewQueue.SendByFormatName();
            myNewQueue.MonitorComputerJournal();
            myNewQueue.MonitorQueueJournal();
            myNewQueue.MonitorDeadLetter();
            myNewQueue.MonitorTransactionalDeadLetter();

            return;
        }
        
        // References public queues.
        public void SendPublic()
        {
            MessageQueue myQueue = new MessageQueue(".\\myQueue");
            myQueue.Send("Public queue by path name.");

            return;
        }

        // References private queues.
        public void SendPrivate()
        {
            MessageQueue myQueue = new
                MessageQueue(".\\Private$\\myQueue");
            myQueue.Send("Private queue by path name.");

            return;
        }

        // References queues by label.
        public void SendByLabel()
        {
            MessageQueue myQueue = new MessageQueue("Label:TheLabel");
            myQueue.Send("Queue by label.");

            return;
        }

        // References queues by format name.
        public void SendByFormatName()
        {
            MessageQueue myQueue = new
                MessageQueue("FormatName:Public=5A5F7535-AE9A-41d4" +
                "-935C-845C2AFF7112");
            myQueue.Send("Queue by format name.");

            return;
        }

        // References computer journal queues.
        public void MonitorComputerJournal()
        {
            MessageQueue computerJournal = new
                MessageQueue(".\\Journal$");
            while(true)
            {
                Message journalMessage = computerJournal.Receive();
                // Process the journal message.
            }
        }

        // References queue journal queues.
        public void MonitorQueueJournal()
        {
            MessageQueue queueJournal = new
                MessageQueue(".\\myQueue\\Journal$");
            while(true)
            {
                Message journalMessage = queueJournal.Receive();
                // Process the journal message.
            }
        }
        
        // References dead-letter queues.
        public void MonitorDeadLetter()
        {
            MessageQueue deadLetter = new
                MessageQueue(".\\DeadLetter$");
            while(true)
            {
                Message deadMessage = deadLetter.Receive();
                // Process the dead-letter message.
            }
        }

        // References transactional dead-letter queues.
        public void MonitorTransactionalDeadLetter()
        {
            MessageQueue TxDeadLetter = new
                MessageQueue(".\\XactDeadLetter$");
            while(true)
            {
                Message txDeadLetter = TxDeadLetter.Receive();
                // Process the transactional dead-letter message.
            }
        }
    }
}

Imports System.Messaging

Public Class MyNewQueue


        
        ' Provides an entry point into the application.
        '		 
        ' This example demonstrates several ways to set
        ' a queue's path.
        

        Public Shared Sub Main()

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

            myNewQueue.SendPublic()
            myNewQueue.SendPrivate()
            myNewQueue.SendByLabel()
            myNewQueue.SendByFormatName()
            myNewQueue.MonitorComputerJournal()
            myNewQueue.MonitorQueueJournal()
            myNewQueue.MonitorDeadLetter()
            myNewQueue.MonitorTransactionalDeadLetter()

            Return

        End Sub


        ' References public queues.
        Public Sub SendPublic()

            Dim myQueue As New MessageQueue(".\myQueue")
            myQueue.Send("Public queue by path name.")

            Return

        End Sub


        ' References private queues.
        Public Sub SendPrivate()

            Dim myQueue As New MessageQueue(".\Private$\myQueue")
            myQueue.Send("Private queue by path name.")

            Return

        End Sub


        ' References queues by label.
        Public Sub SendByLabel()

            Dim myQueue As New MessageQueue("Label:TheLabel")
            myQueue.Send("Queue by label.")

            Return

        End Sub


        ' References queues by format name.
        Public Sub SendByFormatName()

            Dim myQueue As New _
                MessageQueue("FormatName:Public=" + _
                    "5A5F7535-AE9A-41d4-935C-845C2AFF7112")
            myQueue.Send("Queue by format name.")

            Return

        End Sub


        ' References computer journal queues.
        Public Sub MonitorComputerJournal()

            Dim computerJournal As New MessageQueue(".\Journal$")

            While True

                Dim journalMessage As Message = _
                    computerJournal.Receive()

                ' Process the journal message.

            End While

            Return
        End Sub


        ' References queue journal queues.
        Public Sub MonitorQueueJournal()

            Dim queueJournal As New _
                            MessageQueue(".\myQueue\Journal$")

            While True

                Dim journalMessage As Message = _
                    queueJournal.Receive()

                ' Process the journal message.

            End While

            Return
        End Sub


        ' References dead-letter queues.
        Public Sub MonitorDeadLetter()
            Dim deadLetter As New MessageQueue(".\DeadLetter$")

            While True

                Dim deadMessage As Message = deadLetter.Receive()

                ' Process the dead-letter message.

            End While

            Return

        End Sub


        ' References transactional dead-letter queues.
        Public Sub MonitorTransactionalDeadLetter()

            Dim TxDeadLetter As New MessageQueue(".\XactDeadLetter$")

            While True

                Dim txDeadLetterMessage As Message = _
                    TxDeadLetter.Receive()

                ' Process the transactional dead-letter message.

            End While

            Return

        End Sub

End Class

O seguinte exemplo de código envia uma mensagem para uma fila e recebe uma mensagem de uma fila, usando uma classe específica da aplicação chamada Order.

#using <system.dll>
#using <system.messaging.dll>

using namespace System;
using namespace System::Messaging;

// This class represents an object the following example 
// sends to a queue and receives from a queue.
ref class Order
{
public:
   int orderId;
   DateTime orderTime;
};


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

   //*************************************************
   // Sends an Order to a queue.
   //*************************************************
   void SendMessage()
   {
      // Create a new order and set values.
      Order^ sentOrder = gcnew Order;
      sentOrder->orderId = 3;
      sentOrder->orderTime = DateTime::Now;

      // Connect to a queue on the local computer.
      MessageQueue^ myQueue = gcnew MessageQueue( ".\\myQueue" );

      // Send the Order to the queue.
      myQueue->Send( sentOrder );
      return;
   }

   //*************************************************
   // Receives a message containing an Order.
   //*************************************************
   void ReceiveMessage()
   {
      // Connect to the a queue on the local computer.
      MessageQueue^ myQueue = gcnew MessageQueue( ".\\myQueue" );

      // Set the formatter to indicate body contains an Order.
      array<Type^>^p = gcnew array<Type^>(1);
      p[ 0 ] = Order::typeid;
      myQueue->Formatter = gcnew XmlMessageFormatter( p );
      try
      {
         // Receive and format the message. 
         Message^ myMessage = myQueue->Receive();
         Order^ myOrder = static_cast<Order^>(myMessage->Body);

         // Display message information.
         Console::WriteLine( "Order ID: {0}", myOrder->orderId );
         Console::WriteLine( "Sent: {0}", myOrder->orderTime );
      }
      catch ( MessageQueueException^ ) 
      {
         // Handle Message Queuing exceptions.
      }
      // Handle invalid serialization format.
      catch ( InvalidOperationException^ e ) 
      {
         Console::WriteLine( e->Message );
      }

      // Catch other exceptions as necessary.
      return;
   }
};

//*************************************************
// Provides an entry point into the application.
//         
// This example sends and receives a message from
// a queue.
//*************************************************
int main()
{
   // Create a new instance of the class.
   MyNewQueue^ myNewQueue = gcnew MyNewQueue;

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

   // Receive a message from a queue.
   myNewQueue->ReceiveMessage();
   return 0;
}

using System;
using System.Messaging;

namespace MyProject
{

    // This class represents an object the following example
    // sends to a queue and receives from a queue.
    public class Order
    {
        public int orderId;
        public DateTime orderTime;
    };	

    /// <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 queue.
        //**************************************************

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

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

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

            return;
        }

        //**************************************************
        // Sends an Order to a queue.
        //**************************************************
        
        public void SendMessage()
        {
            
            // Create a new order and set values.
            Order sentOrder = new Order();
            sentOrder.orderId = 3;
            sentOrder.orderTime = DateTime.Now;

            // Connect to a queue on the local computer.
            MessageQueue myQueue = new MessageQueue(".\\myQueue");

            // Send the Order to the queue.
            myQueue.Send(sentOrder);

            return;
        }

        //**************************************************
        // Receives a message containing an Order.
        //**************************************************
        
        public  void ReceiveMessage()
        {
            // Connect to the a queue on the local computer.
            MessageQueue myQueue = new MessageQueue(".\\myQueue");

            // Set the formatter to indicate body contains an Order.
            myQueue.Formatter = new XmlMessageFormatter(new Type[]
                {typeof(MyProject.Order)});
            
            try
            {
                // Receive and format the message.
                Message myMessage =	myQueue.Receive();
                Order myOrder = (Order)myMessage.Body;

                // Display message information.
                Console.WriteLine("Order ID: " +
                    myOrder.orderId.ToString());
                Console.WriteLine("Sent: " +
                    myOrder.orderTime.ToString());
            }
            
            catch (MessageQueueException)
            {
                // Handle Message Queuing exceptions.
            }

            // Handle invalid serialization format.
            catch (InvalidOperationException e)
            {
                Console.WriteLine(e.Message);
            }
            
            // Catch other exceptions as necessary.

            return;
        }
    }
}

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

Observações

A tecnologia de Fila de Mensagens permite que aplicações em execução em diferentes momentos comuniquem através de redes heterogéneas e sistemas que podem estar temporariamente offline. As aplicações enviam, recebem ou espreitam (leem sem remover) mensagens das filas. A Fila de Mensagens é um componente opcional do Windows 2000 e do Windows NT, e deve ser instalado separadamente.

A MessageQueue classe é um wrapper em torno da Fila de Mensagens. Existem várias versões do Message Queuing, e usar a MessageQueue classe pode resultar em comportamentos ligeiramente diferentes, dependendo do sistema operativo que está a usar.

A MessageQueue classe fornece uma referência a uma fila de Fila de Mensagens. Pode especificar um caminho no MessageQueue construtor para se ligar a um recurso existente, ou pode criar uma nova fila no servidor. Antes de poder chamar Send(Object), Peek, ou Receive, deve associar a nova instância da MessageQueue classe a uma fila existente. Nesse ponto, pode manipular as propriedades da fila como Category e Label.

MessageQueue suporta dois tipos de recuperação de mensagens: síncrona e assíncrona. Os métodos Peek síncronos e Receive, fazem com que o thread do processo aguarde um intervalo de tempo especificado para que uma nova mensagem chegue à fila. Os métodos assíncronos, BeginPeek e BeginReceive, permitem que as tarefas principais da aplicação continuem numa thread separada até que uma mensagem chegue à fila. Estes métodos funcionam usando objetos de callback e objetos de estado para comunicar informação entre threads.

Quando crias uma nova instância da MessageQueue classe, não estás a criar uma nova fila de Fila de Mensagens. Em vez disso, pode usar os Create(String)métodos , Delete(String), e Purge para gerir filas no servidor.

Ao contrário de Purge, Create(String) e Delete(String) são static membros, por isso podes chamá-los sem criar uma nova instância da MessageQueue classe.

Pode definir a MessageQueue propriedade do Path objeto com um de três nomes: o nome amigo, o FormatName, ou o Label. O nome amigável, que é definido pelas filas MachineName e QueueName propriedades, é MachineNameQueueName\para uma fila pública eQueueNameMachineName\Private$\para uma fila privada. A FormatName propriedade permite acesso offline a filas de mensagens. Por fim, podes usar a propriedade da Label fila para definir a fila Path.

Para obter uma lista de valores das propriedades iniciais de uma instância de MessageQueue, consulte o construtor MessageQueue.

Segurança de Thread

Só que o GetAllMessages() método é seguro para fios.

Ver também

• Message
• DefaultPropertiesToSend
• MessageQueueException
• MessageQueue()
• Peek()
• Receive()
• BeginPeek()
• BeginReceive()
• Path
• Label
• FormatName
• QueueName
• MachineName