【Flutter】ListView、GridView高度自适应并

2021-11-24  本文已影响0人  Piemon_Jay

首先需要一个滚动页面

return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: SingleChildScrollView(
        child: Center(
          child: Wrap(
            children: <Widget>[
              
            ],
          ),
        ),
      ),
    );

按照文档编写ListView和GridView

class Lists extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ListView(
      children: <Widget>[
        ListTile(
          title: Text(
            "我是列表第一项",
            style: TextStyle(color: Colors.red),
          ),
        ),
        ListTile(
          title: Text(
            "我是列表第二项",
            style: TextStyle(color: Colors.yellow),
          ),
        ),
        ListTile(
          title: Text(
            "我是列表第三项",
            style: TextStyle(color: Colors.blue),
          ),
        )
      ],
    );
  }
}

class GridViews extends StatelessWidget {
  List<Widget> _getList() {
    List<Widget> list = new List();
    for (var i = 0; i < 20; i++) {
      list.add(Container(
        alignment: Alignment.center,
        color: Colors.blue.shade50,
        child: Text(
          "第${i + 1}条数据",
          style: TextStyle(color: Colors.red, fontSize: 20),
        ),
      ));
    }
    return list;
  }

  @override
  Widget build(BuildContext context) {
    return GridView.count(
      crossAxisCount: 3,
      mainAxisSpacing: 5, //垂直间距
      crossAxisSpacing: 10, //水平间距
      padding: EdgeInsets.all(10),
      childAspectRatio: 2, //宽高比例
      children: _getList(),
    );
  }
}

把ListView和GridView引入页面

body: SingleChildScrollView(
        child: Center(
          child: Wrap(
            children: <Widget>[
              Lists(),
              GridViews(),
            ],
          ),
        ),
      ),

保存,恭喜你,喜提报错

Cannot hit test a render box that has never been laid out.
当ListView、GridView作为Wrap、Column等组件的子组件时,若外部没有设置高度,则会产生此报错。

若需求高度能够自适应

解决放案:为ListView、GridView设置属性 shrinkWrap: true,

return GridView.count(
      crossAxisCount: 3,
      mainAxisSpacing: 5, //垂直间距
      crossAxisSpacing: 10, //水平间距
      padding: EdgeInsets.all(10),
      childAspectRatio: 2, //宽高比例
      shrinkWrap: true,
      children: _getList(),
    );

刷新后,报错消失,但是发现其只可内部滚动。

若要使其更随外部页面整体滚动,为其设置属性:physics: NeverScrollableScrollPhysics(),
return GridView.count(
      crossAxisCount: 3,
      mainAxisSpacing: 5, //垂直间距
      crossAxisSpacing: 10, //水平间距
      padding: EdgeInsets.all(10),
      childAspectRatio: 2, //宽高比例
      shrinkWrap: true,
      physics: NeverScrollableScrollPhysics(),
      children: _getList(),
    );

至此,需求达成。
参考https://www.jianshu.com/p/60abecfdc51d

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