如何使用父状态小部件更新子StateFulWidget值

Question

我有两个独立的部件。当我单击父小部件中的按钮时，我希望更新子小部件textFormField值。我提供了下面的代码。在没有getX或提供者的情况下，我如何才能做到这一点？我想找一个解决这个问题的办法，但没有找到解决这个问题的办法。

父控件

   FutureBuilder(
              future: SupervisorAttendanceServices.getAttendancesDetailsList(
                  widget.attendanceId),
              builder: (BuildContext context, AsyncSnapshot snapshot) {
                if (snapshot.hasData) {
                  var data = snapshot.data['labour'];
                  return ListView.builder(
                      itemCount: data.length,
                      physics: const NeverScrollableScrollPhysics(),
                      shrinkWrap: true,
                      itemBuilder: (BuildContext context, int index) {
                        return LabourAttendanceWidget(
                            workerId: data[index]['worker_id'],
                            masterAttendanceId: widget.attendanceId,
                            name: data[index]['worker_name'],
                            wages: data[index]['attendance_worker_wages'],
                            isPrensent: data[index]
                                    ['attendance_worker_presense']
                                .toString());
                      });
                } else if (snapshot.hasError) {
                  return const Center(
                    child: Text("Something went wrong !"),
                  );
                } else {
                  return const Center(child: LinearProgressIndicator());
                }
              },
            ),

子部件

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter_feather_icons/flutter_feather_icons.dart';
import 'package:get/get.dart';
import 'package:site_management/supervisors/screens/supervisor_attendance/controller/labour_attendance_controller.dart';
import 'package:site_management/supervisors/supervisor_services/supervisor_attendance_services.dart';

class LabourAttendanceWidget extends StatefulWidget {
  const LabourAttendanceWidget({
    Key? key,
    required this.name,
    required this.wages,
    required this.isPrensent,
    required this.workerId,
    required this.masterAttendanceId,
  }) : super(key: key);
  final int workerId;
  final int masterAttendanceId;
  final String name;
  final String wages;
  final String isPrensent;

  @override
  State<LabourAttendanceWidget> createState() => _LabourAttendanceWidgetState();
}

class _LabourAttendanceWidgetState extends State<LabourAttendanceWidget> {
  final TextEditingController _wagesController = TextEditingController();
  String _character = "";
  Timer? searchOnStoppedTyping;
  LabourAttendanceController attendanceController =
      Get.put(LabourAttendanceController());
  _onChangeHandler(value) {
    const duration = Duration(
        milliseconds:
            800); // set the duration that you want call search() after that.
    if (searchOnStoppedTyping != null) {
      setState(() => searchOnStoppedTyping?.cancel()); // clear timer
    }
    setState(() =>
        searchOnStoppedTyping = Timer(duration, () => submitWages(value)));
  }

  submitWages(value) {
    SupervisorAttendanceServices.storeWorkerWages(
        widget.workerId, value, widget.masterAttendanceId);
  }

  @override
  void initState() {
    super.initState();
    _character = widget.isPrensent;
    _wagesController.text = widget.wages;
    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    return Card(
      child: Column(children: [
        Row(
          crossAxisAlignment: CrossAxisAlignment.center,
          mainAxisAlignment: MainAxisAlignment.start,
          children: [
            const SizedBox(
              width: 10,
              height: 50,
            ),
            const Icon(FeatherIcons.user),
            const SizedBox(
              width: 20,
            ),
            Text(
              widget.name,
              style: const TextStyle(fontSize: 18),
            ),
          ],
        ),
        Row(
          mainAxisAlignment: MainAxisAlignment.spaceAround,
          children: [
            SizedBox(
                width: 150,
                height: 60,
                child: TextFormField(
                  controller: _wagesController,
                  onChanged: _onChangeHandler,
                  decoration: const InputDecoration(
                      // border: OutlineInputBorder(),
                      hintText: "Wages",
                      prefixIcon: Icon(
                        Icons.wallet,
                        color: Colors.blue,
                      )),
                )),
            Row(
              children: [
                Radio(
                  value: "P",
                  groupValue: _character,
                  fillColor:
                      MaterialStateColor.resolveWith((states) => Colors.green),
                  onChanged: (selectedValue) {
                    setState(() {
                      _character = selectedValue.toString();
                      SupervisorAttendanceServices.changeAttendance(
                              widget.workerId,
                              _character,
                              widget.masterAttendanceId)
                          .then((response) {
                        if (response == 1) {
                          return null;
                        } else {
                          ScaffoldMessenger.of(context).showSnackBar(
                            SnackBar(
                              behavior: SnackBarBehavior.floating,
                              content: Row(
                                children: const [
                                  Icon(FeatherIcons.home),
                                  SizedBox(
                                    width: 10,
                                  ),
                                  Text("Something went wrong !"),
                                ],
                              ),
                            ),
                            // sb
                          );
                        }
                      });
                    });
                    attendanceController
                        .getAttendanceCount(widget.masterAttendanceId);
                  },
                ),
                const Text("P"),
                Radio(
                    value: "A",
                    fillColor:
                        MaterialStateColor.resolveWith((states) => Colors.red),
                    groupValue: _character,
                    onChanged: (selectedValue) {
                      setState(() {
                        _wagesController.text = "0";
                        _onChangeHandler("0");
                        _character = selectedValue.toString();
                        SupervisorAttendanceServices.changeAttendance(
                            widget.workerId,
                            _character,
                            widget.masterAttendanceId);
                      });
                      attendanceController
                          .getAttendanceCount(widget.masterAttendanceId);
                    }),
                const Text("A"),
              ],
            )
          ],
        )
      ]),
    );
  }
}

Answer 1

首先，将LabourAttendanceWidget更改为：

class LabourAttendanceWidget extends StatefulWidget {
  const LabourAttendanceWidget({
    Key? key,
    required this.name,
    required this.wages,
    required this.isPrensent,
    required this.workerId,
    required this.masterAttendanceId,
    this.someString,
  }) : super(key: key);
  final int workerId;
  final int masterAttendanceId;
  final String name;
  final String wages;
  final String isPrensent;
  final String someString;

  @override
  State<LabourAttendanceWidget> createState() => _LabourAttendanceWidgetState();
}

然后在LabourAttendanceWidget的initState中这样做：

@override
  void initState() {
    super.initState();
    _character = widget.isPrensent;
    _wagesController.text = widget.someString ?? widget.wages;
    setState(() {});
    
  }

在您的parent小部件中，首先定义这个变量out build方法：

String? _value;

然后这样做：

return LabourAttendanceWidget(
    workerId: data[index]['worker_id'],
    masterAttendanceId: widget.attendanceId,
    name: data[index]['worker_name'],
    wages: data[index]['attendance_worker_wages'],
    someString: _value,
    isPrensent: data[index]
            ['attendance_worker_presense']
        .toString());

然后在弹出回来时填充_value，然后打电话给setstate。