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How to make "items: " equal to a variable length in CarouselSlider?


I am making a news app and I am using CarouselSlider in my flutter app. But the problem is, the API which I am using sometimes shows 9 articles and sometimes 10 articles. I want to set a variable which can hold the value of apidata.length(9/10). But how to set it equal to the number of items in CarouselSlider i.e. if the api is sending only 9 articles then show 9 slides or if 10 then CarouselSlider should only show 10 slides.

CarouselSlider(
  height: 400.0,
  items: [1,2,3,4,5].map((i) { //How to set the items: [dynamic value not static]
    return Builder(
      builder: (BuildContext context) {
        return Container(
          width: MediaQuery.of(context).size.width,
          margin: EdgeInsets.symmetric(horizontal: 5.0),
          decoration: BoxDecoration(
            color: Colors.amber
          ),
          child: Text('text $i', style: TextStyle(fontSize: 16.0),)
        );
      },
    );
  }).toList(),
)

Solution

  • You can use a List to keep data and control length then use map
    code snippet

    List<int> intList = [];
    ... 
      @override
      void initState() {
        intList.add(1);
        intList.add(2);
    ...
    CarouselSlider(
            height: 400.0,
            items: intList.map((i) { //How to set the items: [dynamic value not static]
              return Builder(
                builder: (BuildContext context) {
                  return Container(
                      width: MediaQuery.of(context).size.width,
                      margin: EdgeInsets.symmetric(horizontal: 5.0),
                      decoration: BoxDecoration(
                          color: Colors.amber
                      ),
                      child: Text('text $i', style: TextStyle(fontSize: 16.0),)
                  );
                },
              );
            }).toList(),
          )
    

    full code

    import 'package:flutter/material.dart';
    import 'package:carousel_slider/carousel_slider.dart';
    
    void main() => runApp(MyApp());
    
    class MyApp extends StatelessWidget {
      // 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,
          ),
          home: MyHomePage(title: 'Flutter Demo Home Page'),
        );
      }
    }
    
    class MyHomePage extends StatefulWidget {
      MyHomePage({Key key, 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
      _MyHomePageState createState() => _MyHomePageState();
    }
    
    class _MyHomePageState extends State<MyHomePage> {
      int _counter = 0;
      List<int> intList = [];
    
      @override
      void initState() {
        intList.add(1);
        intList.add(2);
    
        super.initState();
      }
    
      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: CarouselSlider(
            height: 400.0,
            items: intList.map((i) { //How to set the items: [dynamic value not static]
              return Builder(
                builder: (BuildContext context) {
                  return Container(
                      width: MediaQuery.of(context).size.width,
                      margin: EdgeInsets.symmetric(horizontal: 5.0),
                      decoration: BoxDecoration(
                          color: Colors.amber
                      ),
                      child: Text('text $i', style: TextStyle(fontSize: 16.0),)
                  );
                },
              );
            }).toList(),
          ),
          floatingActionButton: FloatingActionButton(
            onPressed: _incrementCounter,
            tooltip: 'Increment',
            child: Icon(Icons.add),
          ), // This trailing comma makes auto-formatting nicer for build methods.
        );
      }
    }
    

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