Flutter GridView.count 在行布局错误中

Question

我是flutter的新手，我想连续绘制一个图像网格。我用了这个例子 Flutter - Layout a Grid但每次出现错误时它都会显示给我

Widget buildView(){
    return new Container(
      color: Colors.white,
      child:
      new Padding(
        padding: EdgeInsets.all(8.0),
        child: new Column(
          children: <Widget>[
            new Row(
              children: <Widget>[
                Flexible(
                  child: new GridView.count(
                      crossAxisCount: 4,
                      childAspectRatio: 1.0,
                      padding: const EdgeInsets.all(4.0),
                      mainAxisSpacing: 4.0,
                      crossAxisSpacing: 4.0,
                      children: <String>[
                        'https://via.placeholder.com/150',
                        'https://via.placeholder.com/150',
                        'https://via.placeholder.com/150',
                        'https://via.placeholder.com/150',
                        'https://via.placeholder.com/150',
                        'https://via.placeholder.com/150',

                      ].map((String url) {
                        return new GridTile(
                            child: new Image.network(url, fit: BoxFit.cover));
                      }).toList()),
                ),
              ],
            ),
              ],
            ),
          ],
        ),
      ),
    );
  }

每次出现此错误“垂直视口(viewport)被赋予无限高度”时，我都会编码

Answer 1

除非您尝试分割行，否则您不需要将 GridView 包装在 Row 中。您可以只使用 GridView。

new GridView.count(
          crossAxisCount: 4,
          childAspectRatio: 1.0,
          padding: const EdgeInsets.all(4.0),
          mainAxisSpacing: 4.0,
          crossAxisSpacing: 4.0,
          children: <String>[
            'https://via.placeholder.com/150',
            'https://via.placeholder.com/150',
            'https://via.placeholder.com/150',
            'https://via.placeholder.com/150',
            'https://via.placeholder.com/150',
            'https://via.placeholder.com/150',

          ].map((String url) {
            return new GridTile(
                child: new Image.network(url, fit: BoxFit.cover));
          }).toList()),

如果你真的想把它包裹在一行中，你需要用一个容器包裹 GridView 并定义一个宽度或包裹在一个灵活的

Row(
        mainAxisSize: MainAxisSize.min,
        children: <Widget>[
          Flexible(
            child: new GridView.count(
                crossAxisCount: 4,
                childAspectRatio: 1.0,
                padding: const EdgeInsets.all(4.0),
                mainAxisSpacing: 4.0,
                crossAxisSpacing: 4.0,
                children: <String>[
                  'https://via.placeholder.com/150',
                  'https://via.placeholder.com/150',
                  'https://via.placeholder.com/150',
                  'https://via.placeholder.com/150',
                  'https://via.placeholder.com/150',
                  'https://via.placeholder.com/150',    

                ].map((String url) {
                  return new GridTile(
                      child: new Image.network(url, fit: BoxFit.cover));
                }).toList()),
          ),
        ],
      ),

如果你得到无限的高度错误，只需用容器或 sizedbox 包裹它并定义一个高度