相關的導致錯誤的小部件是Containerlib\screens\home_screen.dart:18

我無法在行后放置水平串列視圖。我想要這樣的東西..

這是我的代碼（我在單獨的檔案中有那個搜索欄小部件，它作業正常，我還沒有類別 itmes svgs，所以只使用文本作為孩子）這是我的代碼：

class CategoriesListView extends StatelessWidget {
  CategoriesListView({Key? key}) : super(key: key);
  final List<String> _categories = ['Fruits', 'Vegetables', 'Fishes', 'Dairy'];

  Widget categoryWidget(BuildContext context, String title) {
    return Expanded(
      child: Container(
          height: 50,
          width: 50,
          decoration: BoxDecoration(
              shape: BoxShape.circle,
              color: Theme.of(context).primaryColor,
              border: Border.all(color: Theme.of(context).primaryColor)),
          child: Text(title)),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      color: Colors.black,
      margin: margin,
      height: 200,
      child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                Expanded(
                  child: Text(
                    'Category',
                    style: TextStyle(
                        color: Colors.black,
                        fontSize: 15.0,
                        fontWeight: FontWeight.w600),
                  ),
                ),
                TextButton(
                    onPressed: null,
                    child: Text(
                      'See all',
                      style: TextStyle(color: Theme.of(context).primaryColor),
                    )),
              ],
            ),
            ListView(
                physics: NeverScrollableScrollPhysics(),
                shrinkWrap: true,
                scrollDirection: Axis.horizontal,
                children:
                    _categories.map((e) => categoryWidget(context, e)).toList())
          ]),
    );
  }
}

但最終得到：

════════ Exception caught by rendering library ═════════════════════════════════
RenderBox was not laid out: _RenderColoredBox#f3a92
'package:flutter/src/rendering/box.dart':
package:flutter/…/rendering/box.dart:1
Failed assertion: line 1927 pos 12: 'hasSize'

The relevant error-causing widget was
Container
lib\screens\home_screen.dart:18

如果需要任何其他資訊，我隨時準備提供。

uj5u.com熱心網友回復：

這是您的作業代碼

class CategoriesListView extends StatelessWidget {
      CategoriesListView({Key? key}) : super(key: key);
      final List<String> _categories = ['Fruits', 'Vegetables', 'Fishes', 'Dairy'];
    
      Widget categoryWidget(BuildContext context, String title) {
        return Container(
              height: 50,
              width: 50,
              decoration: BoxDecoration(
                  shape: BoxShape.circle,
                  color: Theme.of(context).primaryColor,
                  border: Border.all(color: Theme.of(context).primaryColor)),
              child: Text(title),);
       
      }
    
      @override
      Widget build(BuildContext context) {
        return Container(
          color: Colors.black,
          margin: margin,
          height: 200,
          child: Column(
              mainAxisSize: MainAxisSize.min,
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Row(
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  children: [
                    Expanded(
                      child: Text(
                        'Category',
                        style: TextStyle(
                            color: Colors.black,
                            fontSize: 15.0,
                            fontWeight: FontWeight.w600),
                      ),
                    ),
                    TextButton(
                        onPressed: null,
                        child: Text(
                          'See all',
                          style: TextStyle(color: Theme.of(context).primaryColor),
                        )),
                  ],
                ),
                Expanded(
                child: ListView(
                    physics: NeverScrollableScrollPhysics(),
                    shrinkWrap: true,
                    scrollDirection: Axis.horizontal,
                    children:
                        _categories.map((e) => categoryWidget(context, e)).toList()))
              ]),
        );
      }
    }

uj5u.com熱心網友回復：

控制臺拋出 hasSize 錯誤，因為您的 ListView 未與 Container 包裝在一起。在 Flutter 中， ListView 沒有自己的高度和寬度。所以總是用 Container 包裹你的 ListView 和它的高度。

做一件事：

1. 從容器中洗掉擴展小部件。

2. 用容器包裝你的 ListView。

Container(
      height: 200, // height should be as per your desire
      child: ListView(
               physics: NeverScrollableScrollPhysics(),
                shrinkWrap: true,
              scrollDirection: Axis.horizontal,
              children: _categories.map((e)=>categoryWidget(context,e)).toList(),
            ),
          ),

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