MessageQueue.Close Método

public:
 void Close();

public void Close ();

member this.Close : unit -> unit

Public Sub Close ()

Exemplos

O exemplo de código a seguir fecha uma fila de Enfileiramento de Mensagens.

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

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

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

      // Send a message to the queue.
      myQueue->Send( "My message data1." );

      // Explicitly release resources.
      myQueue->Close();

      // Attempt to reaquire resources.
      myQueue->Send( "My message data2." );
      return;
   }

   // Receives a message from a queue.
   void ReceiveMessage()
   {
      // Connect to the a 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 ] = String::typeid;
      myQueue->Formatter = gcnew XmlMessageFormatter( p );
      try
      {
         // Receive and format the message. 
         Message^ myMessage1 = myQueue->Receive();
         Message^ myMessage2 = myQueue->Receive();
      }
      catch ( MessageQueueException^ ) 
      {
         // Handle sources of any MessageQueueException.
      }
      finally
      {
         // Free resources.
         myQueue->Close();
      }

      return;
   }
};


// Provides an entry point into the application.
// This example closes a queue and frees its 
// resources.
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
{

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

        //**************************************************
        // Provides an entry point into the application.
        //	
        // This example closes a queue and frees its
        // resources.
        //**************************************************

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

            // Send a message to the queue.
            myQueue.Send("My message data1.");
            
            // Explicitly release resources.
            myQueue.Close();

            // Attempt to reacquire resources.
            myQueue.Send("My message data2.");

            return;
        }

        //**************************************************
        // Receives a message from a queue.
        //**************************************************
        
        public  void ReceiveMessage()
        {
            // Connect to the a 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(String)});
            
            try
            {
                // Receive and format the message.
                Message myMessage1 = myQueue.Receive();
                Message myMessage2 = myQueue.Receive();
            }
            
            catch (MessageQueueException)
            {
                // Handle sources of any MessageQueueException.
            }

            // Catch other exceptions as necessary.

            finally
            {
                // Free resources.
                myQueue.Close();
            }

            return;
        }
    }
}

Imports System.Messaging

  
'Provides a container class for the example.

Public Class MyNewQueue



        ' Provides an entry point into the application.
        '	 
        ' This example closes a queue and frees its 
        ' resources.
 

        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 a message to a queue.
 

        Public Sub SendMessage()

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

            ' Send a message to the queue.
            myQueue.Send("My message data1.")

            ' Explicitly release resources.
            myQueue.Close()

            ' Attempt to reacquire resources.
            myQueue.Send("My message data2.")

            Return

        End Sub



        ' Receives a message from a queue.


        Public Sub ReceiveMessage()

            ' Connect to the a 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([String])})

            Try
                ' Receive and format the message. 
                Dim myMessage1 As Message = myQueue.Receive()
                Dim myMessage2 As Message = myQueue.Receive()

            Catch
                ' Handle sources of any MessageQueueException.

                ' Catch other exceptions as necessary.

            Finally

                ' Free resources.
                myQueue.Close()

            End Try

            Return

        End Sub

End Class

Comentários

Close libera todos os recursos associados a um MessageQueue, incluindo recursos compartilhados, se apropriado. O sistema readquire esses recursos automaticamente se eles ainda estiverem disponíveis, por exemplo, quando você chamar o Send(Object) método, como no código C# a seguir.

myMessageQueue.Send("Text 1.");
myMessageQueue.Close();
myMessageQueue.Send("Text 2."); //Resources are re-acquired.

Quando você chama Close, todas as MessageQueue propriedades que acessam diretamente a fila de Enfileiramento de Mensagens são desmarcadas. O Path, DefaultPropertiesToSend, Formattere MessageReadPropertyFilter todos permanecem como estavam.

Close nem sempre libera os identificadores de leitura e gravação em uma fila, pois eles podem ser compartilhados. Você pode executar qualquer uma das seguintes etapas para garantir que Close libere os identificadores de leitura e gravação em uma fila:

• Create o MessageQueue com acesso exclusivo. Para fazer isso, chame o MessageQueue(String, Boolean) construtor ou MessageQueue(String, Boolean, Boolean) e defina o sharedModeDenyReceive parâmetro como true.

• Create o com o MessageQueue cache de conexão desabilitado. Para fazer isso, chame o MessageQueue(String, Boolean, Boolean) construtor e defina o enableConnectionCache parâmetro como false.

• Desabilitar o cache de conexão. Para fazer isso, defina a EnableConnectionCache propriedade como false.

Você deve chamar Close uma fila antes de excluir a fila no servidor de Enfileiramento de Mensagens. Caso contrário, as mensagens enviadas para a fila podem gerar exceções ou aparecer na fila de mensagens mortas.

A tabela a seguir mostra se esse método está disponível em vários modos de Grupo de Trabalho.

Aplica-se a