Dart: Do I have to cancel Stream subscriptions and close StreamSinks?

Question

I know I have to cancel Stream Subscriptions when I no longer want to receive any events. Do I have to this even after I receive a \'Done\' event? Or do I get memor

Answer 1

I found in my case that if I have code like this:

Stream readHackerNews(String path) {  
  StreamController controller = StreamController();

  ......

  return controller.stream;
}

I see a warning message "Close instance of 'dart.core.Sink'." in the Visual Studio Code. In order to fix this warning I added

controller.close()

to the event handler for the OnCancel event, see below:

Stream readHackerNews(String path) {  
  StreamController controller = StreamController();

  //TODO: your code here

  controller.onCancel = () {
    controller.close();
  };

  return controller.stream;
}

Hope this helps!