MessageQueue::Formatter Property

 

Gets or sets the formatter used to serialize an object into or deserialize an object from the body of a message read from or written to the queue.

Namespace:   System.Messaging
Assembly:  System.Messaging (in System.Messaging.dll)

public:
[BrowsableAttribute(false)]
[MessagingDescriptionAttribute("MQ_Formatter")]
property IMessageFormatter^ Formatter {
	IMessageFormatter^ get();
	void set(IMessageFormatter^ value);
}

Property Value

Type: System.Messaging::IMessageFormatter^

The IMessageFormatter that produces a stream to be written to or read from the message body. The default is XmlMessageFormatter.

The Formatter property contains an instance of a formatter object, which transforms messages when your application reads or writes to the queue.

When the application sends message to the queue, the formatter serializes the object into a stream and inserts it into the message body. When reading from a queue, the formatter deserializes the message data into the Body property of a Message.

The XmlMessageFormatter is loosely coupled, so it is not necessary to have the same object type on the sender and receiver when using this format. The ActiveXMessageFormatter and BinaryMessageFormatter serialize the data into binary representation. The ActiveXMessageFormatter is used when sending or receiving COM components.

BinaryMessageFormatter and ActiveXMessageFormatter provide faster throughput than the XmlMessageFormatter. The ActiveXMessageFormatter allows interoperability with Visual Basic 6.0 Message Queuing applications.

When your application sends messages to the queue, the MessageQueue::Formatter applies only to those messages that use the default message properties, DefaultPropertiesToSend. If you send a Message to the queue, Message Queuing uses the formatter defined in the Message::Formatter property to serialize the body instead.

The MessageQueue class will always use a Message to receive or peek a message from the queue. The message is deserialized using the MessageQueue::Formatter property.

The following table shows whether this property is available in various Workgroup modes.

Workgroup mode

Available

Local computer

Yes

Local computer and direct format name

Yes

Remote computer

No

Remote computer and direct format name

Yes

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

#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;

/// <summary>
/// Provides a container class for the example.
/// </summary>
ref class MyNewQueue
{
public:

   //*************************************************
   // Creates a new queue.
   //*************************************************
   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 );
      }

   }


   //*************************************************
   // Sends an image to a queue, using the BinaryMessageFormatter.
   //*************************************************
   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 = gcnew MessageQueue( ".\\myQueue" );
         Message^ myMessage = gcnew Message( myImage,gcnew BinaryMessageFormatter );

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

      return;
   }


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

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

         // Set the formatter to indicate body contains an Order.
         myQueue->Formatter = gcnew BinaryMessageFormatter;

         // Receive and format the message. 
         Message^ myMessage = myQueue->Receive();
         Bitmap^ myImage = static_cast<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;
   }

};


//*************************************************
// 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;

   // 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;
}

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;
}

.NET Framework
Available since 1.1
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