在构建期间调用setState（）或markNeedsBuild（）。重构AKA将GestureDetector放入容器后发生错误

我正在按照本教程创建连续创建的两个容器，单击这些容器时颜色会发生变化。

它使用了更长，更脏的代码版本。

enum GenderType { male, female }

class InputPage extends StatefulWidget {
  @override
  _InputPageState createState() => _InputPageState();
}

class _InputPageState extends State<InputPage> {
  GenderType? selectedGender;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('BMI CALCULATOR'),
      ),
      body: Column(
        children: [
          Expanded(
            child: Row(
              children: [
                Expanded(
                  child: GestureDetector(
                    onTap: () {
                      setState(() {
                        selectedGender = GenderType.male;
                      });
                    },
                    child: ReusableContainer(
                      colour: selectedGender == GenderType.male
                          ? activeCardColor
                          : inactiveContainerColor,
                      containerChild:
                          ContainerChildColumn(FontAwesomeIcons.male, "Male"),
                    ),
                  ),
                ),
                Expanded(
                  child: GestureDetector(
                    onTap: () {
                      setState(() {
                        selectedGender = GenderType.female;
                      });
                    },
                    child: ReusableContainer(
                      colour: selectedGender == GenderType.female
                          ? activeCardColor
                          : inactiveContainerColor,
                      containerChild: ContainerChildColumn(
                          FontAwesomeIcons.female, "Female"),
                    ),
                  ),
                ),
              ],
            ),
          ),

可重复使用的容器

import 'package:flutter/material.dart';
    
    class ReusableContainer extends StatelessWidget {
      ReusableContainer({@required this.colour, this.containerChild});
    
      final Color? colour;
      final Widget? containerChild;
    
      @override
      Widget build(BuildContext context) {
        return Container(
          child: containerChild,
          margin: EdgeInsets.all(8),
          decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(8),
            color: colour,
          ),
        );
      }
    }

但是，在本教程中，我们被要求“重构”并使代码更简洁。因此，我随后将GestureDetector窗口小部件转移到ReusableContainer类。

class ReusableContainer extends StatelessWidget {
  ReusableContainer(
      {@required this.colour, this.containerChild, this.ownOnTap});

  final Color? colour;
  final Widget? containerChild;
  final Function? ownOnTap;

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: ownOnTap?.call(),
      child: Container(
        child: containerChild,
        margin: EdgeInsets.all(8),
        decoration: BoxDecoration(
          borderRadius: BorderRadius.circular(8),
          color: colour,

和

Expanded(
            child: Row(
              children: [
                Expanded(
                  child: ReusableContainer(
                    ownOnTap: () {
                      setState(() {
                        selectedGender = GenderType.male;
                      });
                    },
                    colour: selectedGender == GenderType.male
                        ? activeCardColor
                        : inactiveContainerColor,
                    containerChild:
                        ContainerChildColumn(FontAwesomeIcons.male, "Male"),
                  ),
                ),
                Expanded(
                  child: ReusableContainer(
                    ownOnTap: () {
                      selectedGender = GenderType.female;
                    },
                    colour: selectedGender == GenderType.female
                        ? activeCardColor
                        : inactiveContainerColor,
                    containerChild:
                        ContainerChildColumn(FontAwesomeIcons.female, "Female")

我逐行遵循了本教程，它应该可以正常工作。但是，它在我这边不起作用，而是显示此错误

我尝试删除两个小部件上的SetStates，但错误消失了，但是它没有用，因为按下时代码不会更新，颜色也不会改变。我该如何解决？