错误的代码写法导致的不可预估的结果。

[moqi2011]

请看下面的例子

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

class TestPage extends StatefulWidget {
  const TestPage({Key? key}) : super(key: key);

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

class _TestPageState extends State<TestPage> {
  bool isSelected = false;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            BrnCheckbox(
              radioIndex: 0,
              isSelected: isSelected,
              childOnRight: true,
              mainAxisSize: MainAxisSize.max,
              child: Text("test"),
              onValueChangedAtIndex: (index, value) {
                isSelected = value;
                setState(() {});
              },
            ),
            TestWidget(isSelected),
            TestWidget2(isSelected),
            TextButton(
                onPressed: () {
                  isSelected = !isSelected;
                  setState(() {});
                },
                child: Text("修改"))
          ],
        ),
      ),
    );
  }
}

class TestWidget extends StatefulWidget {
  final bool isSelected;

  const TestWidget(this.isSelected, {Key? key}) : super(key: key);

  @override
  State<TestWidget> createState() => _TestWidgetState();
}

class _TestWidgetState extends State<TestWidget> {
  @override
  Widget build(BuildContext context) {
    return Text("TestWidget:${widget.isSelected}");
  }
}

class TestWidget2 extends StatefulWidget {
  final bool isSelected;

  const TestWidget2(this.isSelected, {Key? key}) : super(key: key);

  @override
  State<TestWidget2> createState() => _TestWidget2State();
}

class _TestWidget2State extends State<TestWidget2> {
  late bool _isSelected;

  @override
  void initState() {
    super.initState();
    _isSelected = widget.isSelected;
    print("call TestWidget2 initState");
  }

  @override
  Widget build(BuildContext context) {
    return Text("TestWidget2:${_isSelected}");
  }
}

理论上讲，我点击【修改】按钮后BrnCheckbox状态应该发生同步变化，但实际上不行，_TestPageState中的isSelected变量无法和BrnCheckbox中的状态同步。原因是调用父亲控件的setState方法，并不会重新创建子控件的State。只会调用子控件的didUpdateWidget方法。类似的在_BrnRadioCoreState有处理didUpdateWidget方法貌似解决了这个问题。我觉得BrnCheckbox这种轻量级控件大可不必设置成StatefulWidget。

[moqi2011]

StatefulWidget的生命周期

[leftcoding]

问题已知晓，请查看提交代码的建议