MessageQueue.Path Property

Definition

Namespace:

System.Messaging

Assembly:

System.Messaging.dll

Gets or sets the queue's path. Setting the Path causes the MessageQueue to point to a new queue.

C#

[System.ComponentModel.Browsable(false)]
[System.Messaging.MessagingDescription("MQ_Path")]
[System.ComponentModel.SettingsBindable(true)]
[System.ComponentModel.TypeConverter("System.Diagnostics.Design.StringValueConverter, System.Design, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")]
public string Path { get; set; }

Property Value

String

The queue that is referenced by the MessageQueue. The default depends on which MessageQueue() constructor you use; it is either null or is specified by the constructor's path parameter.

Attributes

BrowsableAttribute TypeConverterAttribute MessagingDescriptionAttribute SettingsBindableAttribute

Exceptions

ArgumentException

The path is not valid, possibly because the syntax is not valid.

Examples

The following code example creates new MessageQueue objects using various path name syntax types. In each case, it sends a message to the queue whose path is defined in the constructor.

C#

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 demonstrates several ways to set
        // a queue's path.
        //**************************************************

        public static void Main()
        {
            // Create a new instance of the class.
            MyNewQueue myNewQueue = new MyNewQueue();

            myNewQueue.SendPublic();
            myNewQueue.SendPrivate();
            myNewQueue.SendByLabel();
            myNewQueue.SendByFormatName();
            myNewQueue.MonitorComputerJournal();
            myNewQueue.MonitorQueueJournal();
            myNewQueue.MonitorDeadLetter();
            myNewQueue.MonitorTransactionalDeadLetter();

            return;
        }
        
        // References public queues.
        public void SendPublic()
        {
            MessageQueue myQueue = new MessageQueue(".\\myQueue");
            myQueue.Send("Public queue by path name.");

            return;
        }

        // References private queues.
        public void SendPrivate()
        {
            MessageQueue myQueue = new
                MessageQueue(".\\Private$\\myQueue");
            myQueue.Send("Private queue by path name.");

            return;
        }

        // References queues by label.
        public void SendByLabel()
        {
            MessageQueue myQueue = new MessageQueue("Label:TheLabel");
            myQueue.Send("Queue by label.");

            return;
        }

        // References queues by format name.
        public void SendByFormatName()
        {
            MessageQueue myQueue = new
                MessageQueue("FormatName:Public=5A5F7535-AE9A-41d4" +
                "-935C-845C2AFF7112");
            myQueue.Send("Queue by format name.");

            return;
        }

        // References computer journal queues.
        public void MonitorComputerJournal()
        {
            MessageQueue computerJournal = new
                MessageQueue(".\\Journal$");
            while(true)
            {
                Message journalMessage = computerJournal.Receive();
                // Process the journal message.
            }
        }

        // References queue journal queues.
        public void MonitorQueueJournal()
        {
            MessageQueue queueJournal = new
                MessageQueue(".\\myQueue\\Journal$");
            while(true)
            {
                Message journalMessage = queueJournal.Receive();
                // Process the journal message.
            }
        }
        
        // References dead-letter queues.
        public void MonitorDeadLetter()
        {
            MessageQueue deadLetter = new
                MessageQueue(".\\DeadLetter$");
            while(true)
            {
                Message deadMessage = deadLetter.Receive();
                // Process the dead-letter message.
            }
        }

        // References transactional dead-letter queues.
        public void MonitorTransactionalDeadLetter()
        {
            MessageQueue TxDeadLetter = new
                MessageQueue(".\\XactDeadLetter$");
            while(true)
            {
                Message txDeadLetter = TxDeadLetter.Receive();
                // Process the transactional dead-letter message.
            }
        }
    }
}

Remarks

The syntax for the Path property depends on the type of queue it points to, as shown in the following table.

Queue type	Syntax
Public queue	MachineName\QueueName
Private queue	MachineName\Private$\QueueName
Journal queue	MachineName\QueueName\Journal$
Machine journal queue	MachineName\Journal$
Machine dead-letter queue	MachineName\Deadletter$
Machine transactional dead-letter queue	MachineName\XactDeadletter$

Use "." to represent the local computer.

The MachineName, Path, and QueueName properties are related. Changing the MachineName property causes the Path property to change. It is built from the new MachineName and the QueueName. Changing the Path (for example, to use the format name syntax) resets the MachineName and QueueName properties to refer to the new queue.

Alternatively, you can use the FormatName or Label to describe the queue path, as shown in the following table.

Reference	Syntax	Example
Format name	FormatName: [ format name ]	FormatName:Public= 5A5F7535-AE9A-41d4-935C-845C2AFF7112
Label	Label: [ label ]	Label: TheLabel

If you use the label syntax for the Path property when you send the message, an exception will be thrown if the Label is not unique.

To work offline, you must use the format name syntax, rather than the friendly name syntax in the first table. Otherwise, an exception is thrown because the primary domain controller (on which Active Directory resides) is not available to resolve the path to the format name.

Setting a new path closes the message queue and releases all handles.

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	Yes
Remote computer and direct format name	Yes

Note

In workgroup mode you can only use private queues. You specify the path using the private queue syntax MachineName\Private$\QueueName.

Applies to

See also

• QueueName
• MachineName
• FormatName
• Label
• MessageQueue()
• Close()