尝试在Flutter Streambuilder中构建Like/Like Button -不起作用

import 'dart:async';

class LikeBloc {
  final _likeController = StreamController<bool>();
  Stream<bool> get likeStream => _likeController.stream;

  void likeButtonClicked() {
    _likeController.sink.add(true);
  }

  void dispose() {
    _likeController.close();
  }
}

import 'package:flutter/material.dart';

class LikeButton extends StatefulWidget {
  @override
  _LikeButtonState createState() => _LikeButtonState();
}

class _LikeButtonState extends State<LikeButton> {
  final _likeBloc = LikeBloc();

  @override
  void dispose() {
    _likeBloc.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return StreamBuilder<bool>(
      stream: _likeBloc.likeStream,
      initialData: false,
      builder: (context, snapshot) {
        return IconButton(
          icon: Icon(
            snapshot.data ? Icons.favorite : Icons.favorite_border,
            color: snapshot.data ? Colors.red : null,
          ),
          onPressed: () {
            _likeBloc.likeButtonClicked();
          },
        );
      },
    );
  }
}