스크롤 숙제 질문

[쌔뮤얼]

import 'package:flutter/material.dart';
import './style.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';
import 'package:flutter/rendering.dart';

void main() {
  runApp(
      MaterialApp(
        theme:theme,
        home: MyApp()
      )
  );
}

class MyApp extends StatefulWidget {
  const MyApp({super.key});

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  var tab = 0;
  var data = [];

  addData(a) {
    setState(() {
      data.add(a);
    });
  }

  getData() async {
    var result = await http.get( Uri.parse('https://codingapple1.github.io/app/data.json') );
    var result2 = jsonDecode(result.body);
    setState(() {
      data = result2;
    });
  }

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    getData();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Instagram'),
        actions: [
          IconButton(
              onPressed: (){},
              iconSize: 30,
              icon: Icon(Icons.add_box_outlined)),
        ]),
      body: [Home(data : data), Text('shop')]
,
      bottomNavigationBar: BottomNavigationBar(
        showSelectedLabels: false,
        showUnselectedLabels: false,
        onTap: (i){
          setState(() {
            tab = i;
          });
        },
        items: [
          BottomNavigationBarItem(
              label : "home",
              icon: Icon(Icons.home_outlined)),
          BottomNavigationBarItem(
              label: "shop",
              icon: Icon(Icons.shopping_bag_outlined))
        ],
      ),

    );
  }
}

class Home extends StatefulWidget {
  const Home ({Key? key, this.data, this.addData}) : super(key: key);
  final data;
  final addData;

  @override
  State<Home> createState() => _HomeState();
}

class _HomeState extends State<Home> {
  var scroll = ScrollController();

  getMore() async {
    var result = await http.get(Uri.parse("https://codingapple1.github.io/app/more1.json"));
    var result2 = jsonDecode(result.body);
    widget.addData(result2);
  }

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    scroll.addListener(() {
      print(getMore());
      if (scroll.position.pixels == scroll.position.maxScrollExtent){
        getMore();
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    if(widget.data.isNotEmpty) {
      return ListView.builder(itemCount: widget.data.length, controller: scroll, itemBuilder: (c, i){
        return Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Image.network(widget.data[i]['image']),
            Text('좋아요 ${widget.data[i]['likes']}'),
            Text(widget.data[i]['date']),
            Text(widget.data[i]['content']),
          ],
        );
      });
    } else {
      return CircularProgressIndicator();
    }
  }
}

E/flutter (11861): [ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: NoSuchMethodError: The method 'call' was called on null.
E/flutter (11861): Receiver: null
E/flutter (11861): Tried calling: call(_Map len:7)
E/flutter (11861): #0 Object.noSuchMethod (dart:core-patch/object_patch.dart:38:5)
E/flutter (11861): #1 _HomeState.getMore (package:instagram/main.dart:97:19)
E/flutter (11861): <asynchronous suspension>

어떻게 해결해야하는지 모르겠습니다.

[codingapple]

자식으로 addData라는 state 안보낸듯요

[쌔뮤얼]

위에 setState으로 보낸거 아닌가요??

[codingapple]

Home(data : data) 여기 자식쓰는곳에 추가합시다

[글쓴이]

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