addListener method

void addListener({
  1. required String key,
  2. required EventCallback callback,
})

添加监听

Implementation

void addListener({
  required String key,
  required EventCallback callback,
}) {
  if (_events[key] != null) {
    _events[key] = [..._events[key]!, callback];
  } else {
    _events[key] = [callback];
  }
}