简单介绍

GridView是一个网格布局的Widget。

用法

1、GridView.count

class GridViewCountDemo extends StatelessWidget {
  List<Widget> _gridItems(int length) {
    return List.generate(length, (int index) {
      return Container(
        alignment: Alignment(0.0, 0.0),
        color: Colors.grey,
        child: Text(
          'Item $index',
          style: TextStyle(
            color: Colors.red,
            fontSize: 20.0,
          ),
        ),
      );
    });
  }

  @override
  Widget build(BuildContext context) {
    return GridView.count(
      crossAxisCount: 2, /
      crossAxisSpacing: 10.0,
      mainAxisSpacing: 10.0,
      children: _gridItems(100),
    );
  }
}

2、GridView.extent

class GridViewExtentDemo extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    List<Widget> _gridItems(int length) {
      return List.generate(length, (int index) {
        return Container(
          color: Colors.green,
          alignment: Alignment(0.0, 0.0),
          child: Text(
            'item $index',
            style: TextStyle(
              color: Colors.white,
              fontSize: 20.0,
            ),
          ),
        );
      });
    }

    return GridView.extent(
      maxCrossAxisExtent: 200.0, // 相当于网格宽度
      crossAxisSpacing: 10.0,
      mainAxisSpacing: 10.0,
      children: _gridItems(50),
    );
  }
}

3、GridView.builder

网格数量可以自由配置

class GridViewBuildDemo extends StatelessWidget {
  Widget _gridItem(BuildContext context, int index) {
    return Container(
      child: Image.network(
        posts[index].imageUrl,
        fit: BoxFit.cover,
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return GridView.builder(
        padding: EdgeInsets.all(20.0),
        itemCount: posts.length,
        gridDelegate: SliverGridDelegateWithMaxCrossAxisExtent(
//          crossAxisCount: 3,
          maxCrossAxisExtent: 200,
          crossAxisSpacing: 10.0,
          mainAxisSpacing: 10.0,
        ),
        itemBuilder: _gridItem);
  }
}

效果图

GridView