MessageQueue.GetPublicQueuesByCategory(Guid) Method

Reference

Definition

Namespace:: System.Messaging

Assembly:: System.Messaging.dll

Important

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Retrieves all the public queues on the network that belong to the specified category.

public:
 static cli::array <System::Messaging::MessageQueue ^> ^ GetPublicQueuesByCategory(Guid category);

public static System.Messaging.MessageQueue[] GetPublicQueuesByCategory (Guid category);

static member GetPublicQueuesByCategory : Guid -> System.Messaging.MessageQueue[]

Public Shared Function GetPublicQueuesByCategory (category As Guid) As MessageQueue()

Parameters

category: Guid

A Guid that groups the set of queues to be retrieved.

Returns

MessageQueue[]

An array of MessageQueue objects that reference the retrieved public queues.

Exceptions

MessageQueueException

An error occurred when accessing a Message Queuing method.

Examples

The following code example retrieves lists of queues.

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

using namespace System;
using namespace System::Messaging;
using namespace System::Collections;
ref class MyNewQueue
{
public:

   // Gets a list of queues with a specified category.
   // Sends a broadcast message to all queues in that
   // category.
   void GetQueuesByCategory()
   {
      
      // Get a list of queues with the specified category.
      array<MessageQueue^>^QueueList = MessageQueue::GetPublicQueuesByCategory( Guid(" {00000000-0000-0000-0000-000000000001}") );
      
      // Send a broadcast message to each queue in the array.
      IEnumerator^ myEnum = QueueList->GetEnumerator();
      while ( myEnum->MoveNext() )
      {
         MessageQueue^ queueItem = safe_cast<MessageQueue^>(myEnum->Current);
         queueItem->Send( "Broadcast message." );
      }

      return;
   }


   // Gets a list of queues with a specified label.
   // Sends a broadcast message to all queues with that
   // label.
   void GetQueuesByLabel()
   {
      
      // Get a list of queues with the specified label.
      array<MessageQueue^>^QueueList = MessageQueue::GetPublicQueuesByLabel( "My Label" );
      
      // Send a broadcast message to each queue in the array.
      IEnumerator^ myEnum = QueueList->GetEnumerator();
      while ( myEnum->MoveNext() )
      {
         MessageQueue^ queueItem = safe_cast<MessageQueue^>(myEnum->Current);
         queueItem->Send( "Broadcast message." );
      }

      return;
   }


   // Gets a list of queues on a specified computer. 
   // Displays the list on screen.
   void GetQueuesByComputer()
   {
      
      // Get a list of queues on the specified computer.
      array<MessageQueue^>^QueueList = MessageQueue::GetPublicQueuesByMachine( "MyComputer" );
      
      // Display the paths of the queues in the list.
      IEnumerator^ myEnum = QueueList->GetEnumerator();
      while ( myEnum->MoveNext() )
      {
         MessageQueue^ queueItem = safe_cast<MessageQueue^>(myEnum->Current);
         Console::WriteLine( queueItem->Path );
      }

      return;
   }


   // Gets a list of all public queues.
   void GetAllPublicQueues()
   {
      
      // Get a list of public queues.
      array<MessageQueue^>^QueueList = MessageQueue::GetPublicQueues();
      return;
   }


   // Gets a list of all public queues that match 
   // specified criteria. Displays the list on 
   // screen.
   void GetPublicQueuesByCriteria()
   {
      
      // Define criteria to filter the queues.
      MessageQueueCriteria^ myCriteria = gcnew MessageQueueCriteria;
      myCriteria->CreatedAfter = DateTime::Now.Subtract( TimeSpan(1,0,0,0) );
      myCriteria->ModifiedBefore = DateTime::Now;
      myCriteria->MachineName = ".";
      myCriteria->Label = "My Queue";
      
      // Get a list of queues with that criteria.
      array<MessageQueue^>^QueueList = MessageQueue::GetPublicQueues( myCriteria );
      
      // Display the paths of the queues in the list.
      IEnumerator^ myEnum = QueueList->GetEnumerator();
      while ( myEnum->MoveNext() )
      {
         MessageQueue^ queueItem = safe_cast<MessageQueue^>(myEnum->Current);
         Console::WriteLine( queueItem->Path );
      }

      return;
   }


   // Gets a list of private queues on the local 
   // computer. Displays the list on screen.
   void GetPrivateQueues()
   {
      
      // Get a list of queues with the specified category.
      array<MessageQueue^>^QueueList = MessageQueue::GetPrivateQueuesByMachine( "." );
      
      // Display the paths of the queues in the list.
      IEnumerator^ myEnum = QueueList->GetEnumerator();
      while ( myEnum->MoveNext() )
      {
         MessageQueue^ queueItem = safe_cast<MessageQueue^>(myEnum->Current);
         Console::WriteLine( queueItem->Path );
      }

      return;
   }

};


// Provides an entry point into the application.
// This example gets lists of queues by a variety
// of criteria.
int main()
{
   
   // Create a new instance of the class.
   MyNewQueue^ myNewQueue = gcnew MyNewQueue;
   
   // Send normal and high priority messages.
   myNewQueue->GetQueuesByCategory();
   myNewQueue->GetQueuesByLabel();
   myNewQueue->GetQueuesByComputer();
   myNewQueue->GetAllPublicQueues();
   myNewQueue->GetPublicQueuesByCriteria();
   myNewQueue->GetPrivateQueues();
   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 gets lists of queues by a variety
        // of criteria.
        //**************************************************

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

            // Send normal and high priority messages.
            myNewQueue.GetQueuesByCategory();
            myNewQueue.GetQueuesByLabel();
            myNewQueue.GetQueuesByComputer();
            myNewQueue.GetAllPublicQueues();
            myNewQueue.GetPublicQueuesByCriteria();
            myNewQueue.GetPrivateQueues();
                        
            return;
        }

        //**************************************************
        // Gets a list of queues with a specified category.
        // Sends a broadcast message to all queues in that
        // category.
        //**************************************************
        
        public void GetQueuesByCategory()
        {
            // Get a list of queues with the specified category.
            MessageQueue[] QueueList =
                MessageQueue.GetPublicQueuesByCategory(new
                Guid("{00000000-0000-0000-0000-000000000001}"));

            // Send a broadcast message to each queue in the array.
            foreach(MessageQueue queueItem in QueueList)
            {
                queueItem.Send("Broadcast message.");
            }
            
            return;
        }

        //**************************************************
        // Gets a list of queues with a specified label.
        // Sends a broadcast message to all queues with that
        // label.
        //**************************************************
        
        public void GetQueuesByLabel()
        {
            // Get a list of queues with the specified label.
            MessageQueue[] QueueList =
                MessageQueue.GetPublicQueuesByLabel("My Label");

            // Send a broadcast message to each queue in the array.
            foreach(MessageQueue queueItem in QueueList)
            {
                queueItem.Send("Broadcast message.");
            }
            
            return;
        }

        //**************************************************
        // Gets a list of queues on a specified computer.
        // Displays the list on screen.
        //**************************************************
        
        public void GetQueuesByComputer()
        {
            // Get a list of queues on the specified computer.
            MessageQueue[] QueueList =
                MessageQueue.GetPublicQueuesByMachine("MyComputer");

            // Display the paths of the queues in the list.
            foreach(MessageQueue queueItem in QueueList)
            {
                Console.WriteLine(queueItem.Path);
            }

            return;
        }

        //**************************************************
        // Gets a list of all public queues.
        //**************************************************
        
        public void GetAllPublicQueues()
        {
            // Get a list of public queues.
            MessageQueue[] QueueList =
                MessageQueue.GetPublicQueues();
    
            return;
        }

        //**************************************************
        // Gets a list of all public queues that match
        // specified criteria. Displays the list on
        // screen.
        //**************************************************
        
        public void GetPublicQueuesByCriteria()
        {
            // Define criteria to filter the queues.
            MessageQueueCriteria myCriteria = new
                MessageQueueCriteria();
            myCriteria.CreatedAfter = DateTime.Now.Subtract(new
                TimeSpan(1,0,0,0));
            myCriteria.ModifiedBefore = DateTime.Now;
            myCriteria.MachineName = ".";
            myCriteria.Label = "My Queue";
            
            // Get a list of queues with that criteria.
            MessageQueue[] QueueList =
                MessageQueue.GetPublicQueues(myCriteria);

            // Display the paths of the queues in the list.
            foreach(MessageQueue queueItem in QueueList)
            {
                Console.WriteLine(queueItem.Path);
            }

            return;
        }

        //**************************************************
        // Gets a list of private queues on the local
        // computer. Displays the list on screen.
        //**************************************************
        
        public void GetPrivateQueues()
        {
            // Get a list of queues with the specified category.
            MessageQueue[] QueueList =
                MessageQueue.GetPrivateQueuesByMachine(".");

            // Display the paths of the queues in the list.
            foreach(MessageQueue queueItem in QueueList)
            {
                Console.WriteLine(queueItem.Path);
            }
            
            return;
        }
    }
}

Imports System.Messaging

Public Class MyNewQueue


        
        ' Provides an entry point into the application.
        '		 
        ' This example gets lists of queues by a variety
        ' of criteria.


        Public Shared Sub Main()

            ' Create a new instance of the class.
            Dim myNewQueue As New MyNewQueue()

            ' Send normal and high priority messages.
            myNewQueue.GetQueuesByCategory()
            myNewQueue.GetQueuesByLabel()
            myNewQueue.GetQueuesByComputer()
            myNewQueue.GetAllPublicQueues()
            myNewQueue.GetPublicQueuesByCriteria()
            myNewQueue.GetPrivateQueues()

            Return

        End Sub



        ' Gets a list of queues with a specified category.
        ' Sends a broadcast message to all queues in that
        ' category.
 
        Public Sub GetQueuesByCategory()

            ' Get a list of queues with the specified category.
            Dim QueueList As MessageQueue() = _
                MessageQueue.GetPublicQueuesByCategory(New _
                Guid("{00000000-0000-0000-0000-000000000001}"))

            ' Send a broadcast message to each queue in the array.
            Dim queueItem As MessageQueue
            For Each queueItem In QueueList
                queueItem.Send("Broadcast message.")
            Next queueItem

            Return

        End Sub



        ' Gets a list of queues with a specified label.
        ' Sends a broadcast message to all queues with that
        ' label.


        Public Sub GetQueuesByLabel()

            ' Get a list of queues with the specified label.
            Dim QueueList As MessageQueue() = _
                MessageQueue.GetPublicQueuesByLabel("My Label")

            ' Send a broadcast message to each queue in the array.
            Dim queueItem As MessageQueue
            For Each queueItem In QueueList
                queueItem.Send("Broadcast message.")
            Next queueItem

            Return

        End Sub



        ' Gets a list of queues on a specified computer. 
        ' Displays the list on screen.
 

        Public Sub GetQueuesByComputer()

            ' Get a list of queues on the specified computer.
            Dim QueueList As MessageQueue() = _
                MessageQueue.GetPublicQueuesByMachine("MyComputer")

            ' Display the paths of the queues in the list.
            Dim queueItem As MessageQueue
            For Each queueItem In QueueList
                Console.WriteLine(queueItem.Path)
            Next queueItem

            Return

        End Sub



        ' Gets a list of all public queues.
       

        Public Sub GetAllPublicQueues()

            ' Get a list of public queues.
            Dim QueueList As MessageQueue() = _
                MessageQueue.GetPublicQueues()

            Return

        End Sub


 
        ' Gets a list of all public queues that match 
        ' specified criteria. Displays the list on 
        ' screen.


        Public Sub GetPublicQueuesByCriteria()

            ' Define criteria to filter the queues.
            Dim myCriteria As New MessageQueueCriteria()
            myCriteria.CreatedAfter = DateTime.Now.Subtract(New _
                TimeSpan(1, 0, 0, 0))
            myCriteria.ModifiedBefore = DateTime.Now
            myCriteria.MachineName = "."
            myCriteria.Label = "My Queue"

            ' Get a list of queues with that criteria.
            Dim QueueList As MessageQueue() = _
                MessageQueue.GetPublicQueues(myCriteria)

            ' Display the paths of the queues in the list.
            Dim queueItem As MessageQueue
            For Each queueItem In QueueList
                Console.WriteLine(queueItem.Path)
            Next queueItem

            Return

        End Sub


 
        ' Gets a list of private queues on the local 
        ' computer. Displays the list on screen.
  

        Public Sub GetPrivateQueues()

            ' Get a list of queues with the specified category.
            Dim QueueList As MessageQueue() = _
                MessageQueue.GetPrivateQueuesByMachine(".")

            ' Display the paths of the queues in the list.
            Dim queueItem As MessageQueue
            For Each queueItem In QueueList
                Console.WriteLine(queueItem.Path)
            Next queueItem

            Return

        End Sub

End Class

Remarks

Use this method to filter the public queues by category. The Category property provides access to the Message Queuing type ID property (which is read/write) of a particular queue. Although you can use NewGuid to create a category value that is unique across all Guid values, it is not necessary. The category value needs to be distinct only from other categories, not from all other Guid values. For example, you can assign {00000000-0000-0000-0000-000000000001} as the Category for one set of queues and {00000000-0000-0000-0000-000000000002} as the Category for another set.

GetPublicQueuesByCategory(Guid) retrieves a static snapshot of the queues. To interact with a dynamic list of the queues, use GetMessageQueueEnumerator. You can specify the category as part of the MessageQueueCriteria you pass into the method.

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

Workgroup mode	Available
Local computer	No
Local computer and direct format name	No
Remote computer	No
Remote computer and direct format name	No

Applies to

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