Message Class

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.

Provides access to the properties needed to define a Message Queuing message.

public ref class Message : System::ComponentModel::Component

public class Message : System.ComponentModel.Component

type Message = class
    inherit Component

Public Class Message
Inherits Component

Inheritance: Object

MarshalByRefObject

Component
Message

Examples

The following code example demonstrates formatting a message body using BinaryMessageFormatter.

using System;
using System.Messaging;
using System.Drawing;
using System.IO;

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 a queue on the local computer.
            CreateQueue(".\\myQueue");
            
            // Send a message to a queue.
            myNewQueue.SendMessage();

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

            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 an image to a queue, using the BinaryMessageFormatter.
        //**************************************************
        
        public void SendMessage()
        {
            try{

                // Create a new bitmap.
                // The file must be in the \bin\debug or \bin\retail folder, or
                // you must give a full path to its location.
                Image myImage = Bitmap.FromFile("SentImage.bmp");

                // Connect to a queue on the local computer.
                MessageQueue myQueue = new MessageQueue(".\\myQueue");
                
                Message myMessage = new Message(myImage, new BinaryMessageFormatter());

                // Send the image to the queue.
                myQueue.Send(myMessage);
            }
            catch(ArgumentException e)
            {
                Console.WriteLine(e.Message);
            }

            return;
        }

        //**************************************************
        // Receives a message containing an image.
        //**************************************************
        
        public  void ReceiveMessage()
        {
                        
            try
            {

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

                // Set the formatter to indicate body contains an Order.
                myQueue.Formatter = new BinaryMessageFormatter();

                // Receive and format the message.
                System.Messaging.Message myMessage = myQueue.Receive();
                Bitmap myImage = (Bitmap)myMessage.Body;
                
                // This will be saved in the \bin\debug or \bin\retail folder.
                myImage.Save("ReceivedImage.bmp",System.Drawing.Imaging.ImageFormat.Bmp);
            }
            
            catch (MessageQueueException)
            {
                // Handle Message Queuing exceptions.
            }

            // Handle invalid serialization format.
            catch (InvalidOperationException e)
            {
                Console.WriteLine(e.Message);
            }

            catch (IOException e)
            {
                // Handle file access exceptions.
            }
            
            // Catch other exceptions as necessary.

            return;
        }
    }
}

Imports System.Messaging
Imports System.Drawing
Imports System.IO


Namespace MyProj
    _
   
   
   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 a queue on the local computer.
         CreateQueue(".\myQueue")
         
         ' Send a message to a queue.
         myNewQueue.SendMessage()
         
         ' Receive a message from a queue.
         myNewQueue.ReceiveMessage()
         
         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 an image to a queue, using the BinaryMessageFormatter.
      '**************************************************
      Public Sub SendMessage()
         Try
            
            ' Create a new bitmap.
            ' The file must be in the \bin\debug or \bin\retail folder, or
            ' you must give a full path to its location.
            Dim myImage As Image = Bitmap.FromFile("SentImage.bmp")
            
            ' Connect to a queue on the local computer.
            Dim myQueue As New MessageQueue(".\myQueue")
            
            Dim myMessage As New Message(myImage, New BinaryMessageFormatter())
            
            ' Send the image to the queue.
            myQueue.Send(myMessage)
         Catch e As ArgumentException
            Console.WriteLine(e.Message)
         End Try 
         
         Return
      End Sub
      
      
      
      '**************************************************
      ' Receives a message containing an image.
      '**************************************************
      Public Sub ReceiveMessage()
         
         Try
            
            ' Connect to the a queue on the local computer.
            Dim myQueue As New MessageQueue(".\myQueue")
            
            ' Set the formatter to indicate body contains an Order.
            myQueue.Formatter = New BinaryMessageFormatter()
            
            ' Receive and format the message. 
            Dim myMessage As System.Messaging.Message = myQueue.Receive()
            Dim myImage As Bitmap = CType(myMessage.Body, Bitmap)
            
            ' This will be saved in the \bin\debug or \bin\retail folder.
            myImage.Save("ReceivedImage.bmp", System.Drawing.Imaging.ImageFormat.Bmp)
         
         
         
         'Catch
         ' Handle Message Queuing exceptions.
         
         ' Handle invalid serialization format.
         Catch e As InvalidOperationException
            Console.WriteLine(e.Message)
         
         Catch e As IOException
         End Try
         ' Handle file access exceptions.
         
         ' Catch other exceptions as necessary.
         Return
      End Sub
   End Class
End Namespace 'MyProj

The following code example demonstrates formatting a message body using XmlMessageFormatter.

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

using namespace System;
using namespace System::Messaging;
using namespace System::Drawing;
using namespace System::IO;
ref class Order
{
public:
   int orderId;
   DateTime orderTime;
};

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()
   {
      try
      {
         // Create a new order and set values.
         Order^ sentOrder = gcnew Order;
         sentOrder->orderId = 3;
         sentOrder->orderTime = DateTime::Now;

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

         // Create the new order.
         Message^ myMessage = gcnew Message( sentOrder );

         // Send the order to the queue.
         myQueue->Send( myMessage );
      }
      catch ( ArgumentException^ e ) 
      {
         Console::WriteLine( e->Message );
      }

      return;
   }

   void ReceiveMessage()
   {
      // Connect to the a queue 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 ] = Order::typeid;
      myQueue->Formatter = gcnew XmlMessageFormatter( p );
      try
      {
         // Receive and format the message. 
         Message^ myMessage = myQueue->Receive();
         Order^ myOrder = dynamic_cast<Order^>(myMessage->Body);

         // Display message information.
         Console::WriteLine( "Order ID: {0}", myOrder->orderId );
         Console::WriteLine( "Sent: {0}", myOrder->orderTime );
      }
      catch ( MessageQueueException^ ) 
      {
         // Handle Message Queuing exceptions.
      }
      // Handle invalid serialization format.
      catch ( InvalidOperationException^ e ) 
      {
         Console::WriteLine( e->Message );
      }

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

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

   // Create a queue on the local computer.
   MyNewQueue::CreateQueue( ".\\myQueue" );

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

   // Receive a message from a queue.
   myNewQueue->ReceiveMessage();
   return 0;
}

using System;
using System.Messaging;
using System.Drawing;
using System.IO;

namespace MyProject
{

    // The following example
    // sends to a queue and receives from a queue.
    public class Order
    {
        public int orderId;
        public DateTime orderTime;
    };	

    /// <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 a queue on the local computer.
            CreateQueue(".\\myQueue");
            
            // Send a message to a queue.
            myNewQueue.SendMessage();

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

            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 an Order to a queue.
        //**************************************************
        
        public void SendMessage()
        {
            try
            {

                // Create a new order and set values.
                Order sentOrder = new Order();
                sentOrder.orderId = 3;
                sentOrder.orderTime = DateTime.Now;

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

                // Create the new order.
                Message myMessage = new Message(sentOrder);

                // Send the order to the queue.
                myQueue.Send(myMessage);
            }
            catch(ArgumentException e)
            {
                Console.WriteLine(e.Message);
            }

            return;
        }

        //**************************************************
        // Receives a message containing an order.
        //**************************************************
        
        public  void ReceiveMessage()
        {
            // Connect to the a queue 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(MyProject.Order)});
            
            try
            {
                // Receive and format the message.
                Message myMessage =	myQueue.Receive();
                Order myOrder = (Order)myMessage.Body;

                // Display message information.
                Console.WriteLine("Order ID: " +
                    myOrder.orderId.ToString());
                Console.WriteLine("Sent: " +
                    myOrder.orderTime.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
Imports System.Drawing
Imports System.IO



   
' The following example 
' sends to a queue and receives from a queue.
Public Class Order
      Public orderId As Integer
      Public orderTime As DateTime
End Class

   
  
' 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 a queue on the local computer.
      CreateQueue(".\myQueue")
         
      ' Send a message to a queue.
      myNewQueue.SendMessage()
       
      ' Receive a message from a queue.
      myNewQueue.ReceiveMessage()
         
      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 an Order to a queue.

   Public Sub SendMessage()
      Try
            
            ' Create a new order and set values.
            Dim sentOrder As New Order()
            sentOrder.orderId = 3
            sentOrder.orderTime = DateTime.Now
            
            ' Connect to a queue on the local computer.
            Dim myQueue As New MessageQueue(".\myQueue")
            
            
            
            ' Create the new order.
            Dim myMessage As New Message(sentOrder)
            
            ' Send the order to the queue.
            myQueue.Send(myMessage)
      Catch e As ArgumentException
            Console.WriteLine(e.Message)
      End Try 
         
      Return
   End Sub
      
      
      
 
      ' Receives a message containing an order.
 
   Public Sub ReceiveMessage()
         ' Connect to the a queue on the local computer.
         Dim myQueue As New MessageQueue(".\myQueue")
         
         ' Set the formatter to indicate body contains an Order.
         myQueue.Formatter = New XmlMessageFormatter(New Type() {GetType(Order)})
         
         Try
            ' Receive and format the message. 
            Dim myMessage As Message = myQueue.Receive()
            Dim myOrder As Order = CType(myMessage.Body, Order)
            
            ' Display message information.
            Console.WriteLine(("Order ID: " + myOrder.orderId.ToString()))
            Console.WriteLine(("Sent: " + myOrder.orderTime.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

Remarks

Use the Message class to peek or receive messages from a queue, or to have fine control over message properties when sending a message to a queue.

MessageQueue uses the Message class when it peeks or receives messages from queues, because both the MessageQueue.Peek and MessageQueue.Receive methods create a new instance of the Message class and set the instance's properties. The Message class's read-only properties apply to retrieving messages from a queue, while the read/write properties apply to sending and retrieving messages. When MessageQueue peeks or receives a message from a queue, its MessageReadPropertyFilter property determines which of the message's properties are retrieved.

The MessageQueue class's Send method allows you to specify any object type for a message being sent to that queue. You can use the MessageQueue instance's DefaultPropertiesToSend property to specify settings for generic messages sent to the queue. The types of settings include formatter, label, encryption, and authentication. You can also specify values for the appropriate DefaultPropertiesToSend members when you coordinate your messaging application to respond to acknowledgment and report messages. Using a Message instance to send a message to the queue gives you the flexibility to access and modify many of these properties - either for a single message or on a message-by-message basis. Message properties take precedence over DefaultPropertiesToSend.

Message data is stored in the Body property and to a lesser extent, the AppSpecific and Extension properties. When message data is encrypted, serialized, or deserialized, only the contents of the Body property are affected.

The contents of the Body property are serialized when the message is sent, using the Formatter property you specify. The serialized contents are found in the BodyStream property. You can also set the BodyStream property directly, for example, to send a file as the data content of a message. You can change the Body or Formatter properties at any time before sending the message, and the data will be serialized appropriately when you call Send.

The properties defined by the MessageQueue.DefaultPropertiesToSend property apply only to messages that are not of type Message. If you specify the DefaultPropertiesToSend property for a MessageQueue, the identically named properties in a Message instance sent to that queue cause these default properties to be ignored.

For a list of initial property values for an instance of Message, see the Message constructor.

Constructors

Message()	Initializes a new instance of the Message class with an empty body.
Message(Object, IMessageFormatter)	Initializes a new instance of the Message class using the specified formatter to serialize the specified object into the body of the message.
Message(Object)	Initializes a new instance of the Message class, using the XmlMessageFormatter to serialize the specified object into the body of the message.

Fields

InfiniteTimeout

Specifies that no time-out exists.

Properties

AcknowledgeType	Gets or sets the type of acknowledgment message to be returned to the sending application.
Acknowledgment	Gets the classification of acknowledgment that this message represents.
AdministrationQueue	Gets or sets the queue that receives the acknowledgement messages that Message Queuing generates.
AppSpecific	Gets or sets additional, application-specific information.
ArrivedTime	Gets the time that the message arrived in the destination queue.
AttachSenderId	Gets or sets a value that indicates whether the sender ID should be attached to the message.
Authenticated	Gets a value that indicates whether the message was authenticated.
AuthenticationProviderName	Gets or sets the name of the cryptographic provider used to generate the digital signature of the message.
AuthenticationProviderType	Gets or sets the type of cryptographic provider used to generate the digital signature of the message.
Body	Gets or sets the content of the message.
BodyStream	Gets or sets the information in the body of the message.
BodyType	Gets or sets the type of data that the message body contains.
CanRaiseEvents	Gets a value indicating whether the component can raise an event. (Inherited from Component)
ConnectorType	Gets or sets a value that indicates that some message properties typically set by Message Queuing were set by the sending application.
Container	Gets the IContainer that contains the Component. (Inherited from Component)
CorrelationId	Gets or sets the message identifier used by acknowledgment, report, and response messages to reference the original message.
DesignMode	Gets a value that indicates whether the Component is currently in design mode. (Inherited from Component)
DestinationQueue	Gets the intended destination queue for a message.
DestinationSymmetricKey	Gets or sets the symmetric key used to encrypt application-encrypted messages or messages sent to foreign queues.
DigitalSignature	Gets or sets the digital signature that Message Queuing uses to authenticate the message.
EncryptionAlgorithm	Gets or sets the encryption algorithm used to encrypt the body of a private message.
Events	Gets the list of event handlers that are attached to this Component. (Inherited from Component)
Extension	Gets or sets additional, application-defined information associated with the message.
Formatter	Gets or sets the formatter used to serialize an object into or deserialize an object from the message body.
HashAlgorithm	Gets or sets the hashing algorithm that Message Queuing uses when authenticating a message or creating a digital signature for a message.
Id	Gets the message's identifier.
IsFirstInTransaction	Gets a value that indicates whether the message was the first message sent in a transaction.
IsLastInTransaction	Gets a value that indicates whether the message was the last message sent in a transaction.
Label	Gets or sets an application-defined Unicode string that describes the message.
LookupId	Introduced in MSMQ 3.0. Gets the message's lookup identifier.
MessageType	Gets the message type: `Normal`, `Acknowledgment`, or `Report`.
Priority	Gets or sets the message priority, which determines where in the queue the message is placed.
Recoverable	Gets or sets a value that indicates whether the message is guaranteed to be delivered in the event of a computer failure or network problem.
ResponseQueue	Gets or sets the queue that receives application-generated response messages.
SecurityContext	Gets or sets the security context for a message.
SenderCertificate	Gets or sets the security certificate used to authenticate messages.
SenderId	Gets the identifier of the sending user.
SenderVersion	Gets the version of Message Queuing used to send the message.
SentTime	Gets the date and time on the sending computer that the message was sent by the source queue manager.
Site	Gets or sets the ISite of the Component. (Inherited from Component)
SourceMachine	Gets the computer from which the message originated.
TimeToBeReceived	Gets or sets the maximum amount of time for the message to be received from the destination queue.
TimeToReachQueue	Gets or sets the maximum amount of time for the message to reach the queue.
TransactionId	Gets the identifier for the transaction of which the message was a part.
TransactionStatusQueue	Gets the transaction status queue on the source computer.
UseAuthentication	Gets or sets a value that indicates whether the message was (or must be) authenticated before being sent.
UseDeadLetterQueue	Gets or sets a value that indicates whether a copy of the message that could not be delivered should be sent to a dead-letter queue.
UseEncryption	Gets or sets a value that indicates whether to make the message private.
UseJournalQueue	Gets or sets a value that indicates whether a copy of the message should be kept in a machine journal on the originating computer.
UseTracing	Gets or sets a value that indicates whether to trace a message as it moves toward its destination queue.

Methods

CreateObjRef(Type)	Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. (Inherited from MarshalByRefObject)
Dispose()	Releases all resources used by the Component. (Inherited from Component)
Dispose(Boolean)	Releases the unmanaged resources used by the Component and optionally releases the managed resources. (Inherited from Component)
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetLifetimeService()	Obsolete. Retrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject)
GetService(Type)	Returns an object that represents a service provided by the Component or by its Container. (Inherited from Component)
GetType()	Gets the Type of the current instance. (Inherited from Object)
InitializeLifetimeService()	Obsolete. Obtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
MemberwiseClone(Boolean)	Creates a shallow copy of the current MarshalByRefObject object. (Inherited from MarshalByRefObject)
ToString()	Returns a String containing the name of the Component, if any. This method should not be overridden. (Inherited from Component)

Events

Disposed

Occurs when the component is disposed by a call to the Dispose() method.

(Inherited from Component)

Applies to

Del via