context.select uses exceptions in Flutter 3.32.8

[Sansuihe]

After I updated the Flutter sdk from 3.27 to 3.32.8, context.select, like context.watch, will respond by refreshing "builder" whenever any parameter is updated. It's no longer possible to monitor only the change of a certain value as before

[rrousselGit]

I doubt that :)
I assume the issue is something else in your codebase. Maybe when upgrading Flutter, something other than provider caused the rebuild of your widget.

Please share a full example

[Sansuihe]

I doubt that :) I assume the issue is something else in your codebase. Maybe when upgrading Flutter, something other than provider caused the rebuild of your widget.

Please share a full example

demo 1

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

/// AppState
class AppState with ChangeNotifier {
  bool _isShow = false;
  bool _isShow2 = false;
  bool get isShow => _isShow;
  bool get isShow2 => _isShow2;

  void setIsShow(){
    _isShow = !_isShow;
    notifyListeners();
  }

  void setIsShow2(){
    _isShow2 = !_isShow2;
    notifyListeners();
  }
}

void main() {
  runApp(
    MultiProvider(
      providers: [ChangeNotifierProvider<AppState>.value(value: AppState(),),],
      child: const MyApp(),
    ),
  );
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: TestPage(),
    );
  }
}

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

  @override
  State<TestPage> createState() => _TestPageState();
}

class _TestPageState extends State<TestPage> {
  @override
  Widget build(BuildContext context) {
    print("==> _build");
    return Scaffold(
      appBar: AppBar(title: Text('TestPage2'),),
      body: Column(
        children: [
          _buildTest(),
          _buildTest2(),
        ],
      ),
    );
  }

  Widget _buildTest() {
    bool isShow = context.select((AppState provider) => provider.isShow);
    print("==> _buildTest");
    return TextButton(
      onPressed: () => context.read<AppState>().setIsShow(),
      child: Text("set: isShow = ${isShow}"),
    );
  }

  Widget _buildTest2() {
    print("==> _buildTest2");
    bool isShow2 = context.select((AppState provider) => provider.isShow2);
    bool isShow = context.read<AppState>().isShow;
    return TextButton(
      onPressed: () => context.read<AppState>().setIsShow2(),
      child: Text("set: isShow = ${isShow} \n  isShow2 = ${isShow2}"),
    );
  }
}

demo 2

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

/// AppState
class AppState with ChangeNotifier {
  bool _isShow = false;
  bool _isShow2 = false;
  bool get isShow => _isShow;
  bool get isShow2 => _isShow2;

  void setIsShow(){
    _isShow = !_isShow;
    notifyListeners();
  }

  void setIsShow2(){
    _isShow2 = !_isShow2;
    notifyListeners();
  }
}

void main() {
  runApp(
    MultiProvider(
      providers: [
        ChangeNotifierProvider<AppState>.value(value: AppState(),),
      ],
      child: const MyApp(),
    ),
  );
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: TestPage(),
    );
  }
}

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

  @override
  State<TestPage> createState() => _TestPageState();
}

class _TestPageState extends State<TestPage> {
  @override
  Widget build(BuildContext context) {
    print("==> _build");
    return Scaffold(
      appBar: AppBar(title: Text('TestPage2'),),
      body: Column(
        children: [
          _buildTest(),
          _buildTest2(),
        ],
      ),
    );
  }

  Widget _buildTest() {
    print("_buildTest");
    return Consumer<AppState>(
      builder: (context, counter, child) {
        return TextButton(
          onPressed:  (){
            context.read<AppState>().setIsShow();
          },
          child: Text('set: isShow:${counter.isShow}',),
        );
      },
    );
  }

  Widget _buildTest2() {
    print("==> _buildTest2");
    bool isShow2 = context.select((AppState provider) => provider.isShow2);
    bool isShow = context.read<AppState>().isShow;
    return TextButton(
      onPressed: () => context.read<AppState>().setIsShow2(),
      child: Text("set: isShow = ${isShow} \n  isShow2 = ${isShow2}"),
    );
  }
}

You can try the following two demonstrations. After clicking the button to refresh, the content you see on the console will be different @ @rrousselGit

[Sansuihe]

select

@rrousselGit After the select is added, the update method is executed. All widgets output the corresponding content in the console. Is this correct?

[mehulcs]

Should work as expected after converting _buildTest and _buildTest2 to a StatelessWidget

[LiWenHui96]

我也发现了这个问题，context.select会触发build

[Sansuihe]

我也发现了这个问题，context.select会触发build

提了半年了，好像并没有人去在意这个这个issues。