Provider

Provider 的使用

添加 provider 依赖

dependencies:
  ...
  # 状态管理
  provider: ^4.0.5
  ...

新建 Provider

import 'package:flutter/material.dart';

class CountProvider with ChangeNotifier {
  int count = 0;

  changeCount(int newNum) {
    count = newNum;
    notifyListeners();
  }
}

页面包裹 Provider

import 'package:provider/provider.dart';

class CountPageState extends StatefulWidget {
  @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider(
      create: (_) => CountProvider(),
      child: ...,
    );
  }
}

获取或修改当前状态

// 取值
int count = Provider.of<CountProvider>(context).count;

// 设置值
Provider.of<CountProvider>(context, listen: false).changeCount(index);