Message.Priority Propriété

Référence

Définition

Espace de noms:: System.Messaging

Assembly:: System.Messaging.dll

Important

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Obtient ou définit la priorité du message, qui détermine la position du message dans la file d'attente.

public:
 property System::Messaging::MessagePriority Priority { System::Messaging::MessagePriority get(); void set(System::Messaging::MessagePriority value); };

[System.Messaging.MessagingDescription("MsgPriority")]
public System.Messaging.MessagePriority Priority { get; set; }

[<System.Messaging.MessagingDescription("MsgPriority")>]
member this.Priority : System.Messaging.MessagePriority with get, set

Public Property Priority As MessagePriority

Valeur de propriété

MessagePriority

Une des valeurs MessagePriority qui représentent les niveaux de priorité des messages non transactionnels. La valeur par défaut est Normal.

Attributs: MessagingDescriptionAttribute

Exceptions

InvalidOperationException

La file d'attente des messages est filtrée pour ignorer la propriété Priority.

Exemples

L’exemple de code suivant envoie deux messages de priorités différentes à la file d’attente et les récupère par la suite.


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

using namespace System;
using namespace System::Messaging;

/// <summary>
/// Provides a container class for the example.
/// </summary>
ref class MyNewQueue
{
   //**************************************************
   // Sends a string message to a queue.
   //**************************************************
public:
   void SendMessage( MessagePriority priority, String^ messageBody )
   {
      // Connect to a queue on the local computer.
      MessageQueue^ myQueue = gcnew MessageQueue( ".\\myQueue" );

      // Create a new message.
      Message^ myMessage = gcnew Message;
      if ( priority > MessagePriority::Normal )
      {
         myMessage->Body = "High Priority: {0}",messageBody;
      }
      else
      {
         myMessage->Body = messageBody;
      }

      // Set the priority of the message.
      myMessage->Priority = priority;

      // Send the Order to the queue.
      myQueue->Send( myMessage );

      return;
   }

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

      // Set the queue to read the priority. By default, it
      // is not read.
      myQueue->MessageReadPropertyFilter->Priority = true;

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

         // Display message information.
         Console::WriteLine( "Priority: {0}",
            myMessage->Priority );
         Console::WriteLine( "Body: {0}",
            myMessage->Body );
      }
      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 messages to a queue.
   myNewQueue->SendMessage( MessagePriority::Normal, "First Message Body." );
   myNewQueue->SendMessage( MessagePriority::Highest, "Second Message Body." );

   // Receive messages from a queue.
   myNewQueue->ReceiveMessage();
   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 sends and receives a message from
        // a queue.
        //**************************************************

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

            // Send messages to a queue.
            myNewQueue.SendMessage(MessagePriority.Normal, "First Message Body.");
            myNewQueue.SendMessage(MessagePriority.Highest, "Second Message Body.");

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

            return;
        }

        //**************************************************
        // Sends a string message to a queue.
        //**************************************************
        
        public void SendMessage(MessagePriority priority, string messageBody)
        {

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

            // Create a new message.
            Message myMessage = new Message();

            if(priority > MessagePriority.Normal)
            {
                myMessage.Body = "High Priority: " + messageBody;
            }
            else
            {
                myMessage.Body = messageBody;
            }

            // Set the priority of the message.
            myMessage.Priority = priority;

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

            return;
        }

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

            // Set the queue to read the priority. By default, it
            // is not read.
            myQueue.MessageReadPropertyFilter.Priority = true;

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

                // Display message information.
                Console.WriteLine("Priority: " +
                    myMessage.Priority.ToString());
                Console.WriteLine("Body: " +
                    myMessage.Body.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


'Provides a container class for the example.
Public Class MyNewQueue
      
      

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

      Public Shared Sub Main()
         ' Create a new instance of the class.
         Dim myNewQueue As New MyNewQueue()
         
         ' Send messages to a queue.
         myNewQueue.SendMessage(MessagePriority.Normal, "First Message Body.")
         myNewQueue.SendMessage(MessagePriority.Highest, "Second Message Body.")
         
         ' Receive messages from a queue.
         myNewQueue.ReceiveMessage()
         myNewQueue.ReceiveMessage()
         
         Return
      End Sub
      
      
      

      ' Sends a string message to a queue.

      Public Sub SendMessage(priority As MessagePriority, messageBody As String)
         
         ' Connect to a queue on the local computer.
         Dim myQueue As New MessageQueue(".\myQueue")
         
         ' Create a new message.
         Dim myMessage As New Message()
         
         If priority > MessagePriority.Normal Then
            myMessage.Body = "High Priority: " + messageBody
         Else
            myMessage.Body = messageBody
         End If 
         ' Set the priority of the message.
         myMessage.Priority = priority
         
         
         ' Send the Order to the queue.
         myQueue.Send(myMessage)
         
         Return
      End Sub
      
      
      

      ' Receives a message.

      Public Sub ReceiveMessage()
         ' Connect to the a queue on the local computer.
         Dim myQueue As New MessageQueue(".\myQueue")
         
         ' Set the queue to read the priority. By default, it
         ' is not read.
         myQueue.MessageReadPropertyFilter.Priority = True
         
         ' Set the formatter to indicate body contains a string.
         myQueue.Formatter = New XmlMessageFormatter(New Type() {GetType(String)})
         
         Try
            ' Receive and format the message. 
            Dim myMessage As Message = myQueue.Receive()
            
            ' Display message information.
            Console.WriteLine(("Priority: " + myMessage.Priority.ToString()))
            Console.WriteLine(("Body: " + myMessage.Body.ToString()))
         
         
         
         ' Handle invalid serialization format.
         Catch e As InvalidOperationException
            Console.WriteLine(e.Message)
         End Try
         
         ' Catch other exceptions as necessary.
         Return
      End Sub
   End Class

Remarques

La Priority propriété affecte la façon dont Message Queuing gère le message pendant qu’il est en route et une fois qu’il atteint sa destination. Les messages dont la priorité est la plus élevée sont prioritaires pendant le routage et sont insérés au début de la file d'attente de destination. Les messages de priorité identique sont placés dans la file d'attente en fonction de leur heure d'arrivée.

Vous pouvez définir une priorité significative uniquement pour les messages non transactionnels. Message Queuing définit automatiquement la priorité des messages transactionnels sur Lowest, ce qui entraîne l’ignorer.

S’applique à