Dart未处理异常：类型'list'不是类型'family'的子类型，-Flutter

Question

Family_View.Dart

class FamilyView extends StatelessWidget {
  Widget familyMember(BuildContext context) {
    var family = Provider.of<Family>(context);

    CollectionReference ref = FirebaseFirestore.instance.collection("users");

    ref.doc(user.uid)..get().then((val) {
      family = val["family"];
      print(family);
    });

    return ListView.builder(
        itemBuilder: (BuildContext context, int index) {
          return Container(
            child: Column(
              children: [
                ListTile(
                  title: Text(family[index]["name"]),
                ),
                Divider(
                  height: 2,
                ),
              ],
            ),
          );
        },
        itemCount: family.length);
  }

family_provider.dart

import 'package:flutter/material.dart';

class Family with ChangeNotifier {
  List _family = [];

  List get family {
    return [..._family];
  }
}

Answer 1

我看不出这个代码有什么问题，如果family是你所说的，它是一个包含[{“name”：“killian”}]的列表，它应该可以工作。

我试了一下，没发现问题

  Widget build(BuildContext context) {
List<dynamic> family = [{'name': 'Killian'}, [{'name': 'Killian'}, {'name': 'Killian'}]];
return Scaffold(

  body: Center(
    child: ListView.builder(
    itemBuilder: (BuildContext context, int index) {
      return Container(
        child: Column(
          children: [
            ListTile(
              title: Text(family[1][index]["name"]),
            ),
            Divider(
              height: 2,
            ),
          ],
        ),
      );
    },
    itemCount: family.length,))
  );    
}

最终出现在屏幕上的是一些列表，他们说基利安相当于家庭名单的lenght。