Question

我在侧栏中排了一行

ListView.builder(
                shrinkWrap: true,
                physics: AlwaysScrollableScrollPhysics(),
                scrollDirection: Axis.vertical,
                itemCount: snapshot.data.length,
                itemBuilder: (BuildContext context, int index) {
                  return Column(
                    children: <Widget>[
                      SizedBox(
                        height: 3.0,
                      ),
                      Row(
                        mainAxisSize: MainAxisSize.max,
                        //crossAxisAlignment: CrossAxisAlignment.start,
                        mainAxisAlignment: MainAxisAlignment.spaceBetween,
                        children: <Widget>[
                          Flexible(child:Text(
                            snapshot.data[index].name1,
                            style: TextStyle(
                              color: Colors.grey,
                            ),
                            //width: 100.0,
                          ),
                          flex: 3,),
                          Flexible(child: Text(
                            'Qty: ${snapshot.data[index].qty}',
                            style: TextStyle(
                              color: Colors.grey,
                            ),

                          ),
                            flex: 1,),

                          Text(
                            '\$ ${snapshot.data[index].price1}',
                            style: TextStyle(
                              color: Colors.black,
                            ),
                          ),

                        ],
                      ),
                      SizedBox(
                        height: 3.0,
                      ),
                    ],
                  );
                },
              );

我无法按行排列数据，就像行数据没有正确对齐

我想以正确的对齐方式

这样的输出

我在这里使用列表视图生成器中的行，因为在列表视图中动态显示数据，我如何为该数据设置适当的垂直对齐方式？

Answer 1

使用“展开式”替换“柔性式”，在最后一个“文本”小部件中添加“展开式”
数量和美元符号可以使用Row分隔以获得更好的格式
还要在“数量”和“美元符号”之间添加填充
您可以在下面看到完整的代码

代码段

Column(
            children: <Widget>[
              SizedBox(
                height: 3.0,
              ),
              Row(
                //mainAxisSize: MainAxisSize.max,
                crossAxisAlignment: CrossAxisAlignment.start,
                mainAxisAlignment: MainAxisAlignment.start,
                children: <Widget>[
                  Expanded(
                    child: Text(
                      snapshot.data[index].name1,
                      style: TextStyle(
                        color: Colors.grey,
                      ),
                      //width: 100.0,
                    ),
                    flex: 3,
                  ),
                  Expanded(
                    child: Row(
                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
                      children: <Widget>[
                        Text(
                          ' Qty ',
                          style: TextStyle(
                            color: Colors.grey,
                          ),
                        ),
                        Text(
                          '  ${snapshot.data[index].qty}',
                          style: TextStyle(
                            color: Colors.grey,
                          ),
                        ),
                      ],
                    ),
                    flex: 1,
                  ),
                  Padding(padding: EdgeInsets.only(left: 8.0)),
                  Expanded(
                      child: Row(
                        mainAxisAlignment: MainAxisAlignment.spaceBetween,
                        children: <Widget>[
                          Text(
                            ' \$',
                            style: TextStyle(
                              color: Colors.black,
                            ),
                          ),
                          Text(
                            ' ${snapshot.data[index].price1}',
                            style: TextStyle(
                              color: Colors.black,
                            ),
                          ),
                        ],
                      ),
                      flex: 1),
                ],
              ),
              SizedBox(
                height: 3.0,
              ),
            ],
          );

完整代码

import 'package:flutter/material.dart';
// To parse this JSON data, do
//
//     final snapshot = snapshotFromJson(jsonString);

import 'dart:convert';

Snapshot snapshotFromJson(String str) => Snapshot.fromJson(json.decode(str));

String snapshotToJson(Snapshot data) => json.encode(data.toJson());

class Snapshot {
  List<Datum> data;

  Snapshot({
    this.data,
  });

  factory Snapshot.fromJson(Map<String, dynamic> json) => Snapshot(
        data: json["data"] == null
            ? null
            : List<Datum>.from(json["data"].map((x) => Datum.fromJson(x))),
      );

  Map<String, dynamic> toJson() => {
        "data": data == null
            ? null
            : List<dynamic>.from(data.map((x) => x.toJson())),
      };
}

class Datum {
  String name1;
  int qty;
  int price1;

  Datum({
    this.name1,
    this.qty,
    this.price1,
  });

  factory Datum.fromJson(Map<String, dynamic> json) => Datum(
        name1: json["name1"] == null ? null : json["name1"],
        qty: json["qty"] == null ? null : json["qty"],
        price1: json["price1"] == null ? null : json["price1"],
      );

  Map<String, dynamic> toJson() => {
        "name1": name1 == null ? null : name1,
        "qty": qty == null ? null : qty,
        "price1": price1 == null ? null : price1,
      };
}

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<Datum> listDatum = [];

  Snapshot snapshot = Snapshot();
  @override
  void initState() {
    listDatum.add(Datum(name1: "abcsfdasdf", qty: 123, price1: 456));
    listDatum.add(Datum(name1: "defa", qty: 23, price1: 4456));
    listDatum.add(Datum(name1: "gggadfa", qty: 1123, price1: 123456));
    snapshot.data = listDatum;

    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: ListView.builder(
        shrinkWrap: true,
        physics: AlwaysScrollableScrollPhysics(),
        scrollDirection: Axis.vertical,
        itemCount: snapshot.data.length,
        itemBuilder: (BuildContext context, int index) {
          return Column(
            children: <Widget>[
              SizedBox(
                height: 3.0,
              ),
              Row(
                //mainAxisSize: MainAxisSize.max,
                crossAxisAlignment: CrossAxisAlignment.start,
                mainAxisAlignment: MainAxisAlignment.start,
                children: <Widget>[
                  Expanded(
                    child: Text(
                      snapshot.data[index].name1,
                      style: TextStyle(
                        color: Colors.grey,
                      ),
                      //width: 100.0,
                    ),
                    flex: 3,
                  ),
                  Expanded(
                    child: Row(
                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
                      children: <Widget>[
                        Text(
                          ' Qty ',
                          style: TextStyle(
                            color: Colors.grey,
                          ),
                        ),
                        Text(
                          '  ${snapshot.data[index].qty}',
                          style: TextStyle(
                            color: Colors.grey,
                          ),
                        ),
                      ],
                    ),
                    flex: 1,
                  ),
                  Padding(padding: EdgeInsets.only(left: 8.0)),
                  Expanded(
                      child: Row(
                        mainAxisAlignment: MainAxisAlignment.spaceBetween,
                        children: <Widget>[
                          Text(
                            ' \$',
                            style: TextStyle(
                              color: Colors.black,
                            ),
                          ),
                          Text(
                            ' ${snapshot.data[index].price1}',
                            style: TextStyle(
                              color: Colors.black,
                            ),
                          ),
                        ],
                      ),
                      flex: 1),
                ],
              ),
              SizedBox(
                height: 3.0,
              ),
            ],
          );
        },
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

如何在行数据波动中设置对齐方式？

1 个答案: