MessagePropertyFilter.Priority Eigenschap

public:
 property bool Priority { bool get(); void set(bool value); };

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

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

Public Property Priority As Boolean

Waarde van eigenschap

trueom informatie te ontvangenPriority; anders. false De standaardwaarde is false.

Kenmerken

MessagingDescriptionAttribute

Voorbeelden

In het volgende codevoorbeeld worden twee berichten met verschillende prioriteiten naar de wachtrij verzonden en vervolgens opgehaald.

#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

Opmerkingen

De Priority eigenschap van de Message klasse is van invloed op de manier waarop Message Queuing het bericht verwerkt terwijl het onderweg is, en waar het bericht in de wachtrij wordt geplaatst wanneer het de bestemming bereikt.

Berichtprioriteit kan alleen zinvol worden ingesteld voor niet-transactionele berichten. De prioriteit voor transactionele berichten wordt automatisch ingesteld op nul, waardoor transactionele berichtprioriteit wordt genegeerd.

Zie ook

• Priority
• MessageQueue