Why is QueueClient not disposable? It has a Close method. Do I always have to call close. The documentation says:
Sends a cleanup message to Service Bus to signal the completion of the usage of an entity. (Inherited from ClientEntity.)
Do I need this if I only use the client for sending?
Because
Reusing factories and clients Service Bus client objects, such as QueueClient or MessageSender, are created through a MessagingFactory object, which also provides internal management of connections. It is recommended that you do not close messaging factories or queue, topic, and subscription clients after you send a message, and then re-create them when you send the next message. Closing a messaging factory deletes the connection to the Service Bus service, and a new connection is established when recreating the factory. Establishing a connection is an expensive operation that you can avoid by reusing the same factory and client objects for multiple operations. You can safely use these client objects for concurrent asynchronous operations and from multiple threads.