C# 4 and .NET 4

1366 ❘ ChaPTer 46 messAGe QueuinG
queue TyPe
Public queue
Private queue
Journal queue
Machine journal queue
Machine dead-letter queue
Machine transactional dead-letter queue
xynTaX
MachineName\QueueName
MachineName\Private$\QueueName
MachineName\QueueName\Journal$
MachineName\Journal$
MachineName\DeadLetter$
MachineName\XactDeadLetter$
When you use the pathname to open public queues, it is necessary to pass the machine name. If the machine
name is not known, the format name can be used instead. The pathname for private queues can be used only
on the local system. The format name must be used to access private queues remotely.
format name
Instead of the pathname, you can use the format name to open a queue. The format name is used for
searching the queue in the Active Directory to get the host where the queue is located. In a disconnected
environment where the queue cannot be reached at the time the message is sent, it is necessary to use the
format name:
MessageQueue queue = new MessageQueue(
@"FormatName:PUBLIC=09816AFF-3608-4c5d-B892-69754BA151FF");
The format name has some different uses. It can be used to open private queues and to specify a protocol
that should be used:
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To access a private queue, the string that has to be passed to the constructor is FormatName:
PRIVATE=MachineGUID\QueueNumber. The queue number for private queues is generated when the
queue is created. You can see the queue numbers in the \System32\msmq\storage\lqs
directory.
With FormatName:DIRECT=Protocol:MachineAddress\QueueName, you can specify the protocol
that should be used to send the message. The HTTP protocol is supported since Message Queuing 3.0.
FormatName:DIRECT=OS:MachineName\QueueName is another way to specify a queue using the
format name. This way you don’t have to specify the protocol but still can use the machine name with
the format name.
sending a message
You can use the Send method of the MessageQueue class to send a message to the queue. The object
passed as an argument of the Send() method is serialized to the associated queue. The Send() method is
overloaded so that a label and a MessageQueueTransaction object can be passed. Transactional behavior
of Message Queuing is discussed later.
The code example first checks if the queue exists. If it doesn’t exist, a queue is created. Then the queue is
opened and the message Sample Message is sent to the queue using the Send() method.
The pathname specifies a dot (just like a period) for the server name, which is the local system. Pathnames
to private queues work only locally:
using System;
using System.Messaging;
namespace Wrox.ProCSharp.Messaging
{
class Program
{
static void Main()
{
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