Flutter Stream 简单的使用

一  简单使用

import 'dart:async';

import 'package:flutter/material.dart';

class HomePage extends StatefulWidget {
  const HomePage({super.key});

  @override
  State createState() => _HomePageState();
}

class _HomePageState extends State {
  /// 1 创建
  StreamController> _dataController = StreamController();

  /// 2 获取streamSink 做 add 入口
  StreamSink get _dataSink => _dataController.sink;

  /// 3 获取Stream 用于监听
  Stream> get _dataStream => _dataController.stream;

  /// 4 事件订阅对象
  StreamSubscription? _dataSubScription;

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    // 监听事件
    _dataSubScription = _dataStream.listen((event) {
      print(event);
    });
  }

  onClick() {
    // 改变事件
    _dataSink.add(["111"]);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text("data"),
        ),
        body: Column(
          children: [ElevatedButton(onPressed: onClick, child: Text("触发事件"))],
        ));
  }

  @override
  void dispose() {
    // TODO: implement dispose
    _dataSubScription!.cancel();
    _dataController.close();
    super.dispose();
  }
}

二 一个栗子

请求网络数据创建流

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:dio/dio.dart';

class HomePage extends StatefulWidget {
  const HomePage({super.key});

  @override
  State createState() => _HomePageState();
}

class _HomePageState extends State {
  static Dio _dio =
      Dio(BaseOptions(baseUrl: "https://interface.meiriyiwen.com"));

  static Future