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flutterdart

using custom external widgets flutters


i am new to flutter and am trying to find out what is wrong with my code, I am trying to display a list in body, using an external file, can anyone point me in the write direction or tell me what i am doing wrong with file_list.dart

Current nothing display from file_list.dart when I run code, but when insert ListTile in main directly it works, is there a step i am missing

I am looking to try and do something like this:

I am a reactJS programmer so flutter a bit new to me

export default const CustomComponent = () => {

return (
 <ul>
  <li>
    tests
 </li>
</ul>
)
}

const main = () => {
return (
<div>
  <Component/>
  <CustomComponent />
</div>
)
}

file_list.dart

import 'package:flutter/material.dart';

class BodyWidget extends StatelessWidget {
  const BodyWidget({
    Key? key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Stack(
      children: <Widget>[
       ListView(
          children: const <Widget>[
            ListTile(
              leading: Icon(Icons.map),
              title: Text('Map'),
            ),
            ListTile(
              leading: Icon(Icons.photo_album),
              title: Text('Album'),
            ),
            ListTile(
              leading: Icon(Icons.phone),
              title: Text('Phone'),
            ),
          ],
        ),
      ],
    );
  }
}

main.dart

import 'package:flutter/material.dart';
import 'components/file_list.dart';

void main() {
  runApp(const MyApp());
}

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

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
        scaffoldBackgroundColor: const Color(0xFFA83232),
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key, required this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Invoke "debug painting" (press "p" in the console, choose the
          // "Toggle Debug Paint" action from the Flutter Inspector in Android
          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
          // to see the wireframe for each widget.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          mainAxisAlignment: MainAxisAlignment.start,
          children: <Widget>[
            BodyWidget() ,
            const Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}


Solution

  • Try this:

    file_list.dart

    import 'package:flutter/material.dart';
    
    class BodyWidget extends StatelessWidget {
      const BodyWidget({
        Key? key,
      }) : super(key: key);
    
      @override
      Widget build(BuildContext context) {
        return ListView(
              children: const <Widget>[
                ListTile(
                  leading: Icon(Icons.map),
                  title: Text('Map'),
                ),
                ListTile(
                  leading: Icon(Icons.photo_album),
                  title: Text('Album'),
                ),
                ListTile(
                  leading: Icon(Icons.phone),
                  title: Text('Phone'),
                ),
              ],
          );
      }
    }
    
    

    main.dart

    import 'package:flutter/material.dart';
    import 'components/file_list.dart';
    
    void main() {
      runApp(const MyApp());
    }
    
    class MyApp extends StatelessWidget {
      const MyApp({Key? key}) : super(key: key);
    
      // This widget is the root of your application.
      @override
      Widget build(BuildContext context) {
        return MaterialApp(
          title: 'Flutter Demo',
          theme: ThemeData(
            // This is the theme of your application.
            //
            // Try running your application with "flutter run". You'll see the
            // application has a blue toolbar. Then, without quitting the app, try
            // changing the primarySwatch below to Colors.green and then invoke
            // "hot reload" (press "r" in the console where you ran "flutter run",
            // or simply save your changes to "hot reload" in a Flutter IDE).
            // Notice that the counter didn't reset back to zero; the application
            // is not restarted.
            primarySwatch: Colors.blue,
            scaffoldBackgroundColor: const Color(0xFFA83232),
          ),
          home: const MyHomePage(title: 'Flutter Demo Home Page'),
        );
      }
    }
    
    class MyHomePage extends StatefulWidget {
      const MyHomePage({Key? key, required this.title}) : super(key: key);
    
      // This widget is the home page of your application. It is stateful, meaning
      // that it has a State object (defined below) that contains fields that affect
      // how it looks.
    
      // This class is the configuration for the state. It holds the values (in this
      // case the title) provided by the parent (in this case the App widget) and
      // used by the build method of the State. Fields in a Widget subclass are
      // always marked "final".
    
      final String title;
    
      @override
      State<MyHomePage> createState() => _MyHomePageState();
    }
    
    class _MyHomePageState extends State<MyHomePage> {
      int _counter = 0;
    
      void _incrementCounter() {
        setState(() {
          // This call to setState tells the Flutter framework that something has
          // changed in this State, which causes it to rerun the build method below
          // so that the display can reflect the updated values. If we changed
          // _counter without calling setState(), then the build method would not be
          // called again, and so nothing would appear to happen.
          _counter++;
        });
      }
    
      @override
      Widget build(BuildContext context) {
        // This method is rerun every time setState is called, for instance as done
        // by the _incrementCounter method above.
        //
        // The Flutter framework has been optimized to make rerunning build methods
        // fast, so that you can just rebuild anything that needs updating rather
        // than having to individually change instances of widgets.
        return Scaffold(
          appBar: AppBar(
            // Here we take the value from the MyHomePage object that was created by
            // the App.build method, and use it to set our appbar title.
            title: Text(widget.title),
          ),
          body: Center(
            // Center is a layout widget. It takes a single child and positions it
            // in the middle of the parent.
            child: Column(
              // Column is also a layout widget. It takes a list of children and
              // arranges them vertically. By default, it sizes itself to fit its
              // children horizontally, and tries to be as tall as its parent.
              //
              // Invoke "debug painting" (press "p" in the console, choose the
              // "Toggle Debug Paint" action from the Flutter Inspector in Android
              // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
              // to see the wireframe for each widget.
              //
              // Column has various properties to control how it sizes itself and
              // how it positions its children. Here we use mainAxisAlignment to
              // center the children vertically; the main axis here is the vertical
              // axis because Columns are vertical (the cross axis would be
              // horizontal).
              mainAxisAlignment: MainAxisAlignment.start,
              children: <Widget>[
                Expanded(
                  child: BodyWidget()
                ),
                const Text(
                  'You have pushed the button this many times:',
                ),
                Text(
                  '$_counter',
                  style: Theme.of(context).textTheme.headline4,
                ),
              ],
            ),
          ),
          floatingActionButton: FloatingActionButton(
            onPressed: _incrementCounter,
            tooltip: 'Increment',
            child: const Icon(Icons.add),
          ), // This trailing comma makes auto-formatting nicer for build methods.
        );
      }
    }