Do I have to dismiss a MFMessageComposeViewController in its didFinishWithResult delegate method?

Question

I'm trying to allow the user to send multiple text messages in succession in a MFMessageComposeViewController, but if I don't dismiss the controller in the didFinishWithResult delegate method, the Cancel button in the top right corner becomes disabled, and the user has no way of getting out of the text message interface.

Is the MFMessageComposeViewController only for sending one-off messages?

func messageComposeViewController(controller: MFMessageComposeViewController!, didFinishWithResult result: MessageComposeResult) {
  if result.value == MessageComposeResultCancelled.value {
    self.dismissViewControllerAnimated(true, completion: nil)
  }
}

Thanks for the help.