如何在 Flutter 中实现 CheckBox？

Question

这里我提到了我的复选框代码。我是 Flutter 的新手，所以我必须实现它以实现记住我的功能。

代码：

 Container(
 padding: EdgeInsets.all(10.0),
  child: Column(
    children: <Widget>[
     new Checkbox(value: checkBoxValue,
          activeColor: Colors.green,
          onChanged:(bool newValue){
        setState(() {
          checkBoxValue = newValue;
        });
       Text('Remember me');
          }),
    ],
  ),
);

Answer 1

如果您需要带有标签的Checkbox，那么您可以使用CheckboxListTile：

CheckboxListTile(
  title: Text("title text"),
  value: checkedValue,
  onChanged: (newValue) {
    setState(() {
      checkedValue = newValue;
    });
  },
  controlAffinity: ListTileControlAffinity.leading,  //  <-- leading Checkbox
)

Answer 2

我不确定我是否正确理解了您的问题，但如果是如何将功能绑定到 Checkbox，则 State 的 StatefulWidget 应该作为您的最小工作示例：

class _MyWidgetState extends State<MyWidget> {
  bool rememberMe = false;

  void _onRememberMeChanged(bool newValue) => setState(() {
    rememberMe = newValue;

    if (rememberMe) {
      // TODO: Here goes your functionality that remembers the user.
    } else {
      // TODO: Forget the user
    }
  });

  @override
  Widget build(BuildContext context) {
    return Checkbox(
      value: rememberMe,
      onChanged: _onRememberMeChanged
    );
  }
}

Answer 3

你试试那个代码，它可以完美运行

Main.dart

import 'package:flutter/material.dart';

import 'checkbox_in_listview_task-7.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',
      debugShowCheckedModeBanner: false,
      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'),
      home: CheckBoxInListview(),
    );   } } 

checkbox_in_listview_task-7.dart

import 'package:flutter/material.dart';

class GetCheckValue extends StatefulWidget {
  @override
  GetCheckValueState createState() {
    return new GetCheckValueState();
  }
}

class GetCheckValueState extends State<GetCheckValue> {
  bool _isChecked = true;
  String _currText = '';

  List<String> text = ["InduceSmile.com", "Flutter.io", "google.com"];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Get check Value Example"),
      ),
      body: Column(
        children: <Widget>[
          Expanded(
            child: Center(
              child: Text(_currText,
                  style: TextStyle(
                    fontSize: 20.0,
                    fontWeight: FontWeight.bold,
                  )),
            ),
          ),
          Expanded(
              child: Container(
            height: 350.0,
            child: Column(
              children: text
                  .map((t) => CheckboxListTile(
                        title: Text(t),
                        value: _isChecked,
                        onChanged: (val) {
                          setState(() {
                            _isChecked = val;
                            if (val == true) {
                              _currText = t;
                            }
                          });
                        },
                      ))
                  .toList(),
            ),
          )),
        ],
      ),
    );
  }
}

它给你输出类似的东西

Answer 4

flutter 中的复选框是一个材料设计小部件。它总是在 Stateful Widget 中使用，因为它不维护自己的状态。我们可以使用它的 onChanged 属性来交互或修改 Flutter 应用中的其他小部件。与大多数其他 Flutter 小部件一样，它还带有许多属性，如 activeColor、checkColor、mouseCursor 等，让开发人员可以完全控制小部件的外观。

例子：

import 'package:flutter/material.dart';

//importing material design liverary
void main() {
runApp(MaterialApp(
    //runApp method
    home: HomePage(),
));//MaterialApp
}

class HomePage extends StatefulWidget {
@override
_HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
bool value = false;

@override
//App widget tree
Widget build(BuildContext context) {
    return MaterialApp(
    home: Scaffold(
        appBar: AppBar(
        title: Text('GeeksforGeeks'),
        backgroundColor: Colors.greenAccent[400],
        leading: IconButton(
            icon: Icon(Icons.menu),
            tooltip: 'Menu',
            onPressed: () {},
        ), //IcoButton
        ), //AppBar
        body: Center(
        /** Card Widget **/
        child: Card(
            child: Padding(
            padding: const EdgeInsets.all(15.0),
            child: SizedBox(
                width: 430,
                height: 700,
                child: Column(
                children: [
                    Text(
                    'Algorithms',
                    style: TextStyle(
                        color: Colors.greenAccent[400],
                        fontSize: 30), //TextStyle
                    ), //Text
                    SizedBox(height: 10),
                    Row(
                    children: <Widget>[
                        SizedBox(
                        width: 10,
                        ), //SizedBox
                        Text(
                        'Liberary Implementation Of Searching Algorithm: ',
                        style: TextStyle(fontSize: 17.0),
                        ), //Text
                        SizedBox(width: 10), //SizedBox
                        /** Checkbox Widget **/
                        Checkbox(
                        value: this.value,
                        onChanged: (bool value) {
                            setState(() {
                            this.value = value;
                            });
                        },
                        ), //Checkbox
                    ], //<Widget>[]
                    ), //Row
                ],
                ), //Column
            ), //SizedBox
            ), //Padding
        ), //Card
        ), //Center//Center
    ), //Scaffold
    ); //MaterialApp
}
}