Message.Id Property

Reference

Definition

Namespace:: System.Messaging

Assembly:: System.Messaging.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Gets the message's identifier.

public:
 property System::String ^ Id { System::String ^ get(); };

[System.Messaging.MessagingDescription("MsgId")]
public string Id { get; }

[<System.Messaging.MessagingDescription("MsgId")>]
member this.Id : string

Public ReadOnly Property Id As String

Property Value

String

The message's unique identifier, which is generated by Message Queuing.

Attributes: MessagingDescriptionAttribute

Exceptions

InvalidOperationException

The message has not been sent. This property can only be read on messages retrieved from a queue.

-or-

The message queue is filtered to ignore the Id property.

Examples

The following code example sends and receives a message containing an order to and from a queue. It specifically requests a positive acknowledgment when the original message reaches or is retrieved from the queue.

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

using namespace System;
using namespace System::Messaging;
ref class MyNewQueue
{
public:
   static void CreateQueue( String^ queuePath )
   {
      try
      {
         if (  !MessageQueue::Exists( queuePath ) )
         {
            MessageQueue::Create( queuePath );
         }
         else
         {
            Console::WriteLine(  "{0} already exists.", queuePath );
         }
      }
      catch ( MessageQueueException^ e ) 
      {
         Console::WriteLine( e->Message );
      }

   }

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

      // Create a new message.
      Message^ myMessage = gcnew Message( "Original Message" );
      myMessage->AdministrationQueue = gcnew MessageQueue( ".\\myAdministrationQueue" );
      myMessage->AcknowledgeType = (AcknowledgeTypes)(AcknowledgeTypes::PositiveReceive | AcknowledgeTypes::PositiveArrival);

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

   String^ ReceiveMessage()
   {
      // Connect to the a queue on the local computer.
      MessageQueue^ myQueue = gcnew MessageQueue( ".\\myQueue" );
      myQueue->MessageReadPropertyFilter->CorrelationId = true;
      array<Type^>^p = gcnew array<Type^>(1);
      p[ 0 ] = String::typeid;
      myQueue->Formatter = gcnew XmlMessageFormatter( p );
      String^ returnString = nullptr;
      try
      {
         // Receive and format the message. 
         Message^ myMessage = myQueue->Receive();

         // Display message information.
         Console::WriteLine( "____________________________________________" );
         Console::WriteLine( "Original message information--" );
         Console::WriteLine( "Body: {0}", myMessage->Body );
         Console::WriteLine( "Id: {0}", myMessage->Id );
         Console::WriteLine( "____________________________________________" );
         returnString = myMessage->Id;
      }
      catch ( MessageQueueException^ ) 
      {
         // Handle Message Queuing exceptions.
      }
      // Handle invalid serialization format.
      catch ( InvalidOperationException^ e ) 
      {
         Console::WriteLine( e->Message );
      }

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

   void ReceiveAcknowledgment( String^ messageId, String^ queuePath )
   {
      bool found = false;
      MessageQueue^ queue = gcnew MessageQueue( queuePath );
      queue->MessageReadPropertyFilter->CorrelationId = true;
      queue->MessageReadPropertyFilter->Acknowledgment = true;
      try
      {
         while ( queue->PeekByCorrelationId( messageId ) != nullptr )
         {
            Message^ myAcknowledgmentMessage = queue->ReceiveByCorrelationId( messageId );

            // Output acknowledgment message information. The correlation Id is identical
            // to the id of the original message.
            Console::WriteLine( "Acknowledgment Message Information--" );
            Console::WriteLine( "Correlation Id: {0}", myAcknowledgmentMessage->CorrelationId );
            Console::WriteLine( "Id: {0}", myAcknowledgmentMessage->Id );
            Console::WriteLine( "Acknowledgment Type: {0}", myAcknowledgmentMessage->Acknowledgment );
            Console::WriteLine( "____________________________________________" );
            found = true;
         }
      }
      catch ( InvalidOperationException^ e ) 
      {
         // This exception would be thrown if there is no (further) acknowledgment message
         // with the specified correlation Id. Only output a message if there are no messages;
         // not if the loop has found at least one.
         if ( found == false )
         {
            Console::WriteLine( e->Message );
         }

         // Handle other causes of invalid operation exception.
      }

   }

};

int main()
{
   // Create a new instance of the class.
   MyNewQueue^ myNewQueue = gcnew MyNewQueue;

   // Create new queues.
   MyNewQueue::CreateQueue( ".\\myQueue" );
   MyNewQueue::CreateQueue( ".\\myAdministrationQueue" );

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

   // Receive messages from a queue.
   String^ messageId = myNewQueue->ReceiveMessage();

   // Receive acknowledgment message.
   if ( messageId != nullptr )
   {
      myNewQueue->ReceiveAcknowledgment( messageId, ".\\myAdministrationQueue" );
   }

   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();

            // Create new queues.
            CreateQueue(".\\myQueue");
            CreateQueue(".\\myAdministrationQueue");

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

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

            // Receive acknowledgment message.
            if(messageId != null)
            {
                myNewQueue.ReceiveAcknowledgment(messageId, ".\\myAdministrationQueue");
            }

            return;
        }

        //**************************************************
        // Creates a new queue.
        //**************************************************

        public static void CreateQueue(string queuePath)
        {
            try	
            {
                if(!MessageQueue.Exists(queuePath))
                {
                    MessageQueue.Create(queuePath);
                }
                else
                {
                    Console.WriteLine(queuePath + " already exists.");
                }
            }
            catch (MessageQueueException e)
            {
                Console.WriteLine(e.Message);
            }
        }

        //**************************************************
        // Sends a string message to a queue.
        //**************************************************
        
        public void SendMessage()
        {

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

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

            myMessage.AdministrationQueue = new MessageQueue(".\\myAdministrationQueue");
            myMessage.AcknowledgeType = AcknowledgeTypes.PositiveReceive | AcknowledgeTypes.PositiveArrival;

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

            return;
        }

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

            myQueue.MessageReadPropertyFilter.CorrelationId = true;

            // Set the formatter to indicate body contains an Order.
            myQueue.Formatter = new XmlMessageFormatter(new Type[]
                {typeof(string)});

            string returnString = null;
            
            try
            {
                // Receive and format the message.
                Message myMessage =	myQueue.Receive();

                // Display message information.
                Console.WriteLine("____________________________________________");
                Console.WriteLine("Original message information--");
                Console.WriteLine("Body: " +myMessage.Body.ToString());
                Console.WriteLine("Id: " + myMessage.Id.ToString());
                Console.WriteLine("____________________________________________");

                returnString =  myMessage.Id;
            }
            
            catch (MessageQueueException)
            {
                // Handle Message Queuing exceptions.
            }

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

            return returnString;
        }

        //**************************************************
        // Receives a message containing an Order.
        //**************************************************
        
        public void ReceiveAcknowledgment(string messageId, string queuePath)
        {
            bool found = false;
            MessageQueue queue = new MessageQueue(queuePath);
            queue.MessageReadPropertyFilter.CorrelationId = true;
            queue.MessageReadPropertyFilter.Acknowledgment = true;

            try
            {
                while(queue.PeekByCorrelationId(messageId) != null)
                {
                    Message myAcknowledgmentMessage = queue.ReceiveByCorrelationId(messageId);
            
                    // Output acknowledgment message information. The correlation Id is identical
                    // to the id of the original message.
                    Console.WriteLine("Acknowledgment Message Information--");
                    Console.WriteLine("Correlation Id: " + myAcknowledgmentMessage.CorrelationId.ToString());
                    Console.WriteLine("Id: " + myAcknowledgmentMessage.Id.ToString());
                    Console.WriteLine("Acknowledgment Type: " + myAcknowledgmentMessage.Acknowledgment.ToString());
                    Console.WriteLine("____________________________________________");

                    found = true;
                }
            }
            catch (InvalidOperationException e)
            {
                // This exception would be thrown if there is no (further) acknowledgment message
                // with the specified correlation Id. Only output a message if there are no messages;
                // not if the loop has found at least one.
                if(found == false)
                {	
                    Console.WriteLine(e.Message);
                }

                // Handle other causes of invalid operation exception.
            }
        }
    }
}

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()
         
         ' Create new queues.
         CreateQueue(".\myQueue")
         CreateQueue(".\myAdministrationQueue")
         
         ' Send messages to a queue.
         myNewQueue.SendMessage()
         
         ' Receive messages from a queue.
         Dim messageId As String = myNewQueue.ReceiveMessage()
         
         ' Receive acknowledgment message.
         If Not (messageId Is Nothing) Then
            myNewQueue.ReceiveAcknowledgment(messageId, ".\myAdministrationQueue")
         End If
         
         Return
   End Sub
      
      
      ' Creates a new queue.

   Public Shared Sub CreateQueue(queuePath As String)
         Try
            If Not MessageQueue.Exists(queuePath) Then
               MessageQueue.Create(queuePath)
            Else
               Console.WriteLine((queuePath + " already exists."))
            End If
         Catch e As MessageQueueException
            Console.WriteLine(e.Message)
         End Try
   End Sub
       
      
      
 
      ' Sends a string message to a queue.
 
   Public Sub SendMessage()
         
         ' Connect to a queue on the local computer.
         Dim myQueue As New MessageQueue(".\myQueue")
         
         ' Create a new message.
         Dim myMessage As New Message("Original Message")
         
         myMessage.AdministrationQueue = New MessageQueue(".\myAdministrationQueue")
         myMessage.AcknowledgeType = AcknowledgeTypes.PositiveReceive Or AcknowledgeTypes.PositiveArrival
         
         ' Send the Order to the queue.
         myQueue.Send(myMessage)
         
         Return
   End Sub
      
      
      
 
      ' Receives a message containing an Order.
 
   Public Function ReceiveMessage() As String
         ' Connect to the a queue on the local computer.
         Dim myQueue As New MessageQueue(".\myQueue")
         
         myQueue.MessageReadPropertyFilter.CorrelationId = True
         
         
         ' Set the formatter to indicate body contains an Order.
         myQueue.Formatter = New XmlMessageFormatter(New Type() {GetType(String)})
         
         Dim returnString As String = Nothing
         
         Try
            ' Receive and format the message. 
            Dim myMessage As Message = myQueue.Receive()
            
            
            ' Display message information.
            Console.WriteLine("____________________________________________")
            Console.WriteLine("Original message information--")
            Console.WriteLine(("Body: " + myMessage.Body.ToString()))
            Console.WriteLine(("Id: " + myMessage.Id.ToString()))
            Console.WriteLine("____________________________________________")
            
            returnString = myMessage.Id
         
         
                  
         ' Handle invalid serialization format.
         Catch e As InvalidOperationException
            Console.WriteLine(e.Message)
         End Try
         
         ' Catch other exceptions as necessary.
         Return returnString
   End Function 'ReceiveMessage
      
      
 
      ' Receives a message containing an Order.
 
   Public Sub ReceiveAcknowledgment(messageId As String, queuePath As String)
         Dim found As Boolean = False
         Dim queue As New MessageQueue(queuePath)
         queue.MessageReadPropertyFilter.CorrelationId = True
         queue.MessageReadPropertyFilter.Acknowledgment = True
         
         Try
            While Not (queue.PeekByCorrelationId(messageId) Is Nothing)
               Dim myAcknowledgmentMessage As Message = queue.ReceiveByCorrelationId(messageId)
               
               ' Output acknowledgment message information. The correlation Id is identical
               ' to the id of the original message.
               Console.WriteLine("Acknowledgment Message Information--")
               Console.WriteLine(("Correlation Id: " + myAcknowledgmentMessage.CorrelationId.ToString()))
               Console.WriteLine(("Id: " + myAcknowledgmentMessage.Id.ToString()))
               Console.WriteLine(("Acknowledgment Type: " + myAcknowledgmentMessage.Acknowledgment.ToString()))
               Console.WriteLine("____________________________________________")
               
               found = True
            End While
         Catch e As InvalidOperationException
            ' This exception would be thrown if there is no (further) acknowledgment message
            ' with the specified correlation Id. Only output a message if there are no messages;
            ' not if the loop has found at least one.
            If found = False Then
               Console.WriteLine(e.Message)
            End If
         End Try 
   End Sub
 End Class

Remarks

Message Queuing generates a message identifier when the message is sent. The identifier is composed of 20 bytes and includes two items: the machine Guid of the sending computer and a unique identifier for the message on the computer. The combination of the two items produces a message identifier that is unique on the network.

Message Queuing generates message identifiers for all messages - including acknowledgment and report messages. An acknowledgment message is generally sent by Message Queuing in reaction to the arrival or failure of an original, sent message. You can find the Id property value of the original message in the CorrelationId property of an acknowledgment message.

You can also use the Id property when sending a response message to a response queue. To include the identifier of the original message in a response message, set the CorrelationId property of the response message to the Id property of the original message. The application reading the response message can then use the correlation identifier of the response message to identify the original message.

Applies to

แชร์ผ่าน