如何在flatter中收缩和扩展Wrap小部件?

LayoutBuilder 小装置。使用这个小部件应该有助于其子部件确定其父部件的约束。既然你提到有一个宽敞的 Container .

这是一个样本。我已经修改了提供的代码段。

import 'package:flutter/material.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(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

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

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final words = ["a", "abc", "de", "ef", "g", "i", "is", "s", "th"];
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Column(children: <Widget>[
        Text('height 100'),
        Container(
          color: Colors.red,
          height: 100.0,
          child: adaptiveText(),
        ),
        Text('height 50'),
        Container(
          color: Colors.green,
          height: 50.0,
          child: adaptiveText(),
        ),
        Text('height 200'),
        Container(
          alignment: Alignment.center,
          color: Colors.blue,
          height: 200.0,
          child: adaptiveText(),
        ),
      ]),
    );
  }

  adaptiveText() {
    return LayoutBuilder(
      builder: (context, constraints) {
        debugPrint('constraint maxHeight: ${constraints.maxHeight}');
        // adapt Text widget if parent widget size is <= 100
        if (constraints.maxHeight <= 100)
          return FittedBox(
            fit: BoxFit.scaleDown,
            child: Wrap(
              alignment: WrapAlignment.spaceEvenly,
              children: _buildWordButtons(words),
            ),
          );
        else
          return Wrap(
            alignment: WrapAlignment.spaceEvenly,
            children: _buildWordButtons(words),
          );
      },
    );
  }

  List<Widget> _buildWordButtons(List<String> words) {
    var buttons = List<Widget>();

    for (var word in words) {
      buttons.add(Container(
        decoration:
            new BoxDecoration(border: new Border.all(color: Colors.black)),
        child: Text(
          word,
          style: TextStyle(fontSize: 50.0),
          maxLines: 3,
        ),
        margin: EdgeInsets.all(5.0),
      ));
    }

    return buttons;
  }
}

演示