MessageQueue::GetPublicQueuesByLabel Method (String^)
Retrieves all the public queues on the network that carry the specified label.
Assembly: System.Messaging (in System.Messaging.dll)
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.
| Exception | Condition |
|---|---|
| MessageQueueException | An error occurred when accessing a Message Queuing method. |
| ArgumentNullException | The label parameter is null. |
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; }
Available since 1.1