MessagePriority MessagePriority MessagePriority MessagePriority Enum

定義

指定訊息佇列在抵達佇列途中以及將訊息插入目的佇列時,套用至訊息的優先權。Specifies the priority Message Queuing applies to a message while it is en route to a queue, and when inserting the message into the destination queue.

public enum class MessagePriority
[System.Serializable]
public enum MessagePriority
type MessagePriority = 
Public Enum MessagePriority
繼承
MessagePriorityMessagePriorityMessagePriorityMessagePriority
屬性

欄位

AboveNormal AboveNormal AboveNormal AboveNormal 4

HighNormal 之間的訊息優先權。Between High and Normal message priority.

High High High High 5

高訊息優先權。High message priority.

Highest Highest Highest Highest 7

最高訊息優先權。Highest message priority.

Low Low Low Low 2

低訊息優先權。Low message priority.

Lowest Lowest Lowest Lowest 0

最低訊息優先權。Lowest message priority.

Normal Normal Normal Normal 3

一般訊息優先權。Normal message priority.

VeryHigh VeryHigh VeryHigh VeryHigh 6

HighestHigh 之間的訊息優先權。Between Highest and High message priority.

VeryLow VeryLow VeryLow VeryLow 1

LowLowest 之間的訊息優先權。Between Low and Lowest message priority.

範例

下列範例會將兩個不同優先順序的訊息傳送至佇列, 並于後續抓取。The following example sends two messages of different priorities to the queue, and retrieves them subsequently.


#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

備註

列舉是由類別的Priority屬性所使用。 Message MessagePriorityThe MessagePriority enumeration is used by the Message class's Priority property. 這個屬性會影響訊息佇列在路由傳送和到達目的地之後, 處理訊息的方式。This property affects how Message Queuing handles the message both while it is en route and once it reaches its destination. 較高優先權的訊息在路由期間會給予喜好設定,並且插入目的端佇列的前端。Higher-priority messages are given preference during routing and inserted toward the front of the destination queue. 優先權相同的訊息會根據抵達時間放置在佇列中。Messages with the same priority are placed in the queue according to their arrival time.

當訊息佇列將訊息路由傳送至公用佇列時, 訊息的優先權層級會新增至公用佇列的優先權層級 (您可以透過MessageQueue類別的BasePriority屬性來存取)。When Message Queuing routes a message to a public queue, the priority level of the message is added to the priority level of the public queue (which you can access through the MessageQueue class's BasePriority property). 佇列的優先權層級不會影響訊息在佇列中的放置方式, 只會顯示訊息佇列在傳送路由時處理訊息的方式。The priority level of the queue has no effect on how messages are placed in the queue, only on how Message Queuing handles the message while en route.

基本優先順序僅適用于公用佇列。Base priority applies only to public queues. 若是私用佇列, 基本優先權一律為零。For a private queue, the base priority is always zero.

您只能針對非交易式訊息設定有意義的優先順序。You can set a meaningful priority only for non-transactional messages. 訊息佇列會自動將交易式訊息的優先順序Lowest設定為, 這會導致忽略交易式訊息優先順序。Message Queuing automatically sets the priority for transactional messages to Lowest, which causes transactional message priority to be ignored.

適用於

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