addListener<T> static method

void addListener<T>(
  1. dynamic target,
  2. void listener(
    1. T value
    )
)

添加监听

Implementation

static void addListener<T>(dynamic target, void Function(T value) listener) {
  if (_listeners.containsKey(target)) {
    _listeners[target]!.add((value) => listener(value as T));
  }
}