Expanded 内的GridView 不可见，仅在使用指定高度的Container 时可见

Question

我有一个网格视图，我想在非特定高度容器中显示它。但是，只有当我使用具有指定高度的容器时，才会显示网格视图。当我将 Container 更改为 Expanded 或 Flexible 时，GridView 变得不可见。

工作代码：

return Container( //using container
  height: 250,    //with a specific height
  child: GridView.count(
    primary: false,
    padding: const EdgeInsets.all(0.0),
    crossAxisSpacing: 10.0,
    crossAxisCount: 2,
    children: <Widget>[
      const Text('He\'d have you all unravel at the'),
      const Text('Heed not the rabble'),
      const Text('Sound of screams but the'),
      const Text('Who scream'),
    ],
  ),
);

非工作代码：

return Expanded(
  child: GridView.count(
    primary: false,
    padding: const EdgeInsets.all(0.0),
    crossAxisSpacing: 10.0,
    crossAxisCount: 2,
    children: <Widget>[
      const Text('He\'d have you all unravel at the'),
      const Text('Heed not the rabble'),
      const Text('Sound of screams but the'),
      const Text('Who scream'),
    ],
  ),
);

Answer 1

gridview的父widget需要有一定的高度。 height: MediaQuery.of(context).size.height 如果容器不可滚动或已发布类似答案，则为选项之一，请参阅link。

Answer 2

你必须扩展成一个 Column Widget，它会占用所有可用的垂直空间

return Column(
    children:<Widget>[
      Expanded(
        child: GridView.count(
          primary: false,
          padding: const EdgeInsets.all(0.0),
          crossAxisSpacing: 10.0,
          crossAxisCount: 2,
          children: <Widget>[
            const Text('He\'d have you all unravel at the'),
            const Text('Heed not the rabble'),
            const Text('Sound of screams but the'),
            const Text('Who scream'),
          ],
        ),
      )
    ]
);