颤动网格视图值不更新

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• 0

  我从下面的代码解决了这个问题 . 我将类 createchildwidget 更改为函数并写入 _MyHomePageState

  import 'dart:async';
    import 'package:flutter/material.dart';
    import 'package:augr/location/LocationScreen.dart';
    import 'package:cloud_firestore/cloud_firestore.dart';
  
    void main() => runApp(MyApp());
  
    class MyApp extends StatelessWidget {
      // This widget is the root of your application.
  
      MyApp({this.firestore});
      final Firestore firestore;
  
  
      @override
      Widget build(BuildContext context) {
        return MaterialApp(
            home: MyHomePage(title: 'My Shop', firestore: firestore)
        );
      }
    }
  
    class MyHomePage extends StatefulWidget {
  
      MyHomePage({Key key, this.title, this.firestore}) : super(key: key);
      final Firestore firestore;
      final String title;
  
      @override
      _MyHomePageState createState() => new _MyHomePageState(firestore: firestore);
    }
  
    class _MyHomePageState extends State<MyHomePage> {
      _MyHomePageState({this.firestore});
      final Firestore firestore;
  
      var documents = [];
      bool isDocLoaded=false;
  
  
      void initState() {
        Firestore.instance.collection("messages").getDocuments().then((data) async {
          var list = data.documents;
          documents = list;
          print("init state document:" +
              documents.length.toString()); // value is getting
          super.initState();
          setState(() {
            isDocLoaded = true;
            documents = list;
          });
        });
      }
  
      @override
      Widget build(BuildContext context) {
        return new Scaffold(
          appBar: new AppBar(
            iconTheme: IconThemeData(
              color: Colors.black, //change font color here
            ),
            backgroundColor: new Color(0xFFFAFAFA),
          )
          title:"title",
          body: isDocLoaded? TheGridview():Center(child:CircularProgressIndicator()),
        );
      }
  
      Widget TheGridView(){
        return GridView.count(
          primary: true,
          padding: EdgeInsets.all(1.0),
          crossAxisCount: 2,
          childAspectRatio: 1.0,
          mainAxisSpacing: 1.0,
          crossAxisSpacing: 1.0,
  
          children: createChildrenTexts(),
  
          /*  children: <Widget>[
                makeGridCell("Home", Icons.access_alarm)
              ],*/
        );
      }
  
      Card makeGridCell(String name, IconData icon){
        return Card(
          elevation: 1.0,
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            mainAxisSize: MainAxisSize.min,
            verticalDirection: VerticalDirection.down,
            children: <Widget>[
              Center(child: Icon(icon)),
              Text(name)
            ],
          ),
        );
      }
      List<Widget> createChildrenTexts(){
        print("createChildrenTexts:"+documents.length.toString()); // the value getting 0
        List<Widget> childrenTexts = List<Widget>();
        for(int i=0;i<documents.length;i++){
          childrenTexts.add(makeGridCell(makeGridCell(data[i].data['message'], Icons.access_alarm));
          }
              return createchildwidget;
          }
    }
  

  回复于 2024-05-16T01:36:10+08:00