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尝试在颤振应用程序中使用一组嵌套的 PopupMenuButtons。第一个菜单按预期打开。第二个菜单只有在多次点击后才会打开，关闭第一个菜单，重新打开它，即随机行为。第三个菜单也是如此。有时第一个或第二个菜单会在未从用户那里收集所有三条信息的情况下过早关闭。我下面的代码有什么问题？？？

import 'dart:convert';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:google_maps_flutter/google_maps_flutter.dart';
import 'package:localstore/localstore.dart';
import 'package:http/http.dart' as http;

late Map<String, dynamic> dirList;
List eventList = [];
List eventYearList = [];
List eventDayList = [];
String eventName = '';
String eventYear = '';
String eventDay = '';
String eventDomain = '';

late Map<String, String> eventInfo;
String eventTitle = "Selecteer een evenement";

// create a list of maptypes, just with the names of the maptypes in Dutch
const List ourMapTypes = ['Wegenkaart', 'Satelliet met labels',
  'Satelliet zonder labels', 'Terrein', 'Open Sea Map'];

void main() {
  WidgetsFlutterBinding.ensureInitialized();
  runApp(MyApp());
}

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

  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {

  late GoogleMapController mapController;
  MapType currentMapType = MapType.normal;
  final LatLng initialMapPosition = const LatLng(52.2, 4.535);

  @override
  void initState() {
    super.initState();
  }

  Future<void> _onMapCreated(GoogleMapController controller) async {
    mapController = controller;

    // Get the list of events ready for selection
    dirList = await fetchDirList();
    dirList.forEach((k, v) => eventList.add(k));
    eventYearList = [];
    eventDayList = [];
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          backgroundColor: Colors.green[900],
          title: PopupMenuButton(
            offset: const Offset(0,40),
            child: Text(eventTitle),
            itemBuilder: (BuildContext context) {
              return eventList.map((events) {
                return PopupMenuItem(
                  height: 30.0,
                  value: events,
                  child: PopupMenuButton(
                    offset: const Offset(30,0),
                    child: Text(events),
                    itemBuilder: (BuildContext context) {
                      return eventYearList.map((years) {
                        return PopupMenuItem(
                          height: 30.0,
                          value: years,
                          child: PopupMenuButton(
                            offset: const Offset(30,0),
                            child: Text(years),
                            itemBuilder: (BuildContext context) {
                              return eventDayList.map((days) {
                                return PopupMenuItem(
                                  height: 30.0,
                                  value: days,
                                  child: Text(days)
                                );
                              }).toList();
                            },
                            onSelected: (eventDayList == []) ? null : newEventSelected,
                          ),
                        );
                      }).toList();
                    },
                    onSelected: (eventYearList == []) ? null : selectEventDay,
                  ),
                );
              }).toList();
            },
            onSelected: selectEventYear,
          ),
          actions: <Widget>[
            PopupMenuButton(
              child: Image.asset('assets/images/mapicon.png'),
              offset: Offset(0,55),
              tooltip: 'Selecteer een kaarttype',
              onSelected: selectMapType,
              itemBuilder: (BuildContext context) {
                return ourMapTypes.map((types) {
                  return PopupMenuItem(
                    height: 30.0,
                    value: types,
                    child: Text(types)
                  );
                }).toList();
              },
            ),
          ],
        ),
        body: GoogleMap(
          onMapCreated: _onMapCreated,
          initialCameraPosition: CameraPosition(
            target: initialMapPosition,
            zoom: 12.0,
          ),
          mapType: currentMapType,
        ),
        bottomNavigationBar: Text('bottombar'),
      ),
    );
  }

  // Routine to change the Type of the map based on the user selection
  void selectMapType(selectedMapType) {
    setState(() {     // Causes the app to rebuild with the selected choice.
      switch (selectedMapType) {
        case "Wegenkaart":
          currentMapType = MapType.normal;
          break;
        case "Satelliet met labels":
          currentMapType = MapType.hybrid;
          break;
        case "Satelliet zonder labels":
          currentMapType = MapType.satellite;
          break;
        case "Terrein":
          currentMapType = MapType.terrain;
          break;
        case "Open Sea Map":
          currentMapType = MapType.normal;
          break;
        default:
          currentMapType = MapType.normal;
          break;
      }
    });
  }

  void selectEventYear(event) {
    setState(() {
      eventName = event;
      eventYearList = [];
      dirList[event].forEach((k, v) => eventYearList.add(k));
      eventYearList = eventYearList.reversed.toList();
      eventDayList = [];
    });
  }

  void selectEventDay(year) {
    setState(() {
      eventYear = year;
      eventDayList = [];
      eventTitle = eventName + '/' + year;
      if (dirList[eventName][eventYear].length != 0) {
        dirList[eventName][eventYear].forEach((k, v) => eventDayList.add(k));
      } else {
        newEventSelected('');
      }
    });
  }

  void newEventSelected(day) {
    setState(() {
      eventDay = day;
      eventDomain = eventName + '/' + eventYear;
      if (eventDay != '') eventDomain = eventDomain + '/' + eventDay;
      eventTitle = eventDomain; // for the time being
      eventYearList = [];
      eventDayList = [];
    });
  }

  Future<Map<String, dynamic>> fetchDirList() async {
    final response = await http
        .get(Uri.parse('https://tt.zeilvaartwarmond.nl/get-dirlist.php?tst=true&msg=simple'));
    if (response.statusCode == 200) {
      return (jsonDecode(response.body));
    } else {
      throw Exception('Failed to load dirList');
    }
  }

}
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1 回答 1

0

的默认行为PopupMenuButton是在选择后关闭它。在使用嵌套PopupMenuButton时，您需要注意context它何时以及如何关闭。

下一个问题来自padding，PopupMenuItem每个项目都没有全尺寸。

您可以使用PopupMenuItem'sonTap或onSelectedfrom PopupMenuButton来查找所选值。如果要更新对话框上的 UI，请选中StatefulBuilder.

这是一个测试片段：

PopupMenuButton(
        child: const Text("POP U"),
        onSelected: (value) {
          print(value);
        },
        itemBuilder: (BuildContext context_p0) {
          return [
            const PopupMenuItem(value: "item: p1", child: Text("Item:p1 ")),
            PopupMenuItem(
              value: "item: p1",
              onTap: () {},
              padding: EdgeInsets.zero,
              child: PopupMenuButton(
                padding: EdgeInsets.zero,
                child: Container(
                  alignment: Alignment.center,
                  height: 48.0, //default height
                  width: double.infinity,
                  child: Text("inner PopUp Menu"),
                ),
                itemBuilder: (context_p1) {
                  return [
                    PopupMenuItem(
                      value: "inner p2",
                      child: Text("inner p2: close with parent "),
                      onTap: () {
                        Navigator.of(context_p1).pop();
                      },
                    ),
                    const PopupMenuItem(
                      value: 'inner p1',
                      child: Text("inner p1, just close this one"),
                    ),
                  ];
                },
              ),
            )
          ];
        },
      ),
于 2022-01-02T14:32:25.447 回答