This documentation is archived and is not being maintained.

MessageQueue::GetPublicQueuesByLabel Method

Retrieves all the public queues on the network that carry the specified label.

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

public:
static array<MessageQueue^>^ GetPublicQueuesByLabel(
	String^ label
)

Parameters

label
Type: System::String
A label that groups the set of queues to be retrieved.

Return Value

Type: array<System.Messaging::MessageQueue>
An array of MessageQueue objects that reference the retrieved public queues.

ExceptionCondition
MessageQueueException

An error occurred when accessing a Message Queuing method.

ArgumentNullException

The label parameter is nullptr.

Use this method to filter the public queues by label.

GetPublicQueuesByLabel(String) retrieves a static snapshot of the queues. To interact with a dynamic list of the queues, use GetMessageQueueEnumerator. You can specify the label 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

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;
}



.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Show: