如何在 Flutter 中为 GridView 中的 Widget 设置自定义高度? [英] How to set Custom height for Widget in GridView in Flutter?

问题描述

即使在为 Container GridView 指定高度后，我的代码仍在生成方形小部件.

Even after specifying the height for Container GridView, my code is producing square widgets.

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

  final String title;

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

class _MyHomePageState extends State<MyHomePage> {
  List<String> widgetList = ['A', 'B', 'C'];

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text(widget.title),
      ),
      body: new Container(
        child: new GridView.count(
          crossAxisCount: 2,
          controller: new ScrollController(keepScrollOffset: false),
          shrinkWrap: true,
          scrollDirection: Axis.vertical,
          children: widgetList.map((String value) {
            return new Container(
              height: 250.0,
              color: Colors.green,
              margin: new EdgeInsets.all(1.0),
              child: new Center(
                child: new Text(
                  value,
                  style: new TextStyle(fontSize: 50.0,color: Colors.white),
                ),
              ),
            );
          }).toList(),
        ),
      ),
    );
  }
}

上面代码的输出如左图所示.如何获得带有自定义高度小部件的 GridView，如右图所示?

The output of the code above is as shown on the left. How can I get a GridView with custom height widget as shown on the right?

推荐答案

关键是childAspectRatio.该值用于确定 GridView 中的布局.为了获得所需的方面，您必须将其设置为 (itemWidth/itemHeight).解决方案是这样的:

The key is the childAspectRatio. This value is use to determine the layout in GridView. In order to get the desired aspect you have to set it to the (itemWidth / itemHeight). The solution would be this:

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

  final String title;

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

class _MyHomePageState extends State<MyHomePage> {
  List<String> widgetList = ['A', 'B', 'C'];

  @override
  Widget build(BuildContext context) {
    var size = MediaQuery.of(context).size;

    /*24 is for notification bar on Android*/
    final double itemHeight = (size.height - kToolbarHeight - 24) / 2;
    final double itemWidth = size.width / 2;

    return new Scaffold(
      appBar: new AppBar(
        title: new Text(widget.title),
      ),
      body: new Container(
        child: new GridView.count(
          crossAxisCount: 2,
          childAspectRatio: (itemWidth / itemHeight),
          controller: new ScrollController(keepScrollOffset: false),
          shrinkWrap: true,
          scrollDirection: Axis.vertical,
          children: widgetList.map((String value) {
            return new Container(
              color: Colors.green,
              margin: new EdgeInsets.all(1.0),
              child: new Center(
                child: new Text(
                  value,
                  style: new TextStyle(
                    fontSize: 50.0,
                    color: Colors.white,
                  ),
                ),
              ),
            );
          }).toList(),
        ),
      ),
    );
  }
}

这篇关于如何在 Flutter 中为 GridView 中的 Widget 设置自定义高度?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！