Flutter：无法使用显示的滚动条创建可水平滚动的主体

Question

我需要帮助来创建可滚动的正文： my screen

这就是我的身体结构：build()

              body: Padding(
                  padding: const EdgeInsets.all(30.0),
                  child: DragAndDropLists(
                    children: _contents,
                    onItemReorder: _onItemReorder,
                    onListReorder: _onListReorder,
                    axis: Axis.horizontal,
                    listWidth: 300,
                    listDraggingWidth: 300,
                    listPadding: EdgeInsets.all(20.0),
                    itemDivider: const Divider(
                      thickness: 4,
                      height: 10,
                      color: lightBlue,
                    ),
                    itemDecorationWhileDragging: BoxDecoration(
                      color: Colors.white,
                      boxShadow: [
                        BoxShadow(
                          color: const Color(0xff004269).withOpacity(0.5),
                          spreadRadius: 2,
                          blurRadius: 3,
                          offset: const Offset(0, 0), // changes position of shadow
                        ),
                      ],
                    ),
                    listInnerDecoration: BoxDecoration(
                      color: Theme.of(context).canvasColor,
                      borderRadius: BorderRadius.all(Radius.circular(5)),
                    ),
                    lastItemTargetHeight: 2,
                    addLastItemTargetHeightToTop: true,
                    lastListTargetSize: 40,
                    
                  ),
                ),

我已经尝试过 ListView、SingleChildScrollView、Column 我不知道为什么，但它不起作用

也许有人知道我可以改变什么来查看滚动条并可以水平滚动它 谢谢

Answer 1

您似乎使用了一些复杂的布局，但简化版本看起来像这样：

您可以将ListView 的scrollDirection 属性设置为Axis.horizontal，对于滚动条，您可以将ListView 包裹在Scrollbar 内。

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatefulWidget {
  MyApp({Key? key}) : super(key: key);

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  final ScrollController _scrollController = ScrollController();

  final List<int> _items = List<int>.generate(100, (int index) => index);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        home: Scaffold(
      body: SizedBox(
        height: 150,
        child: Scrollbar(
          isAlwaysShown: true,
          controller: _scrollController,
          child: ReorderableListView.builder(
            scrollDirection: Axis.horizontal,
            scrollController: _scrollController,
            itemBuilder: buildItem,
            itemCount: _items.length,
            onReorder: (int oldIndex, int newIndex) {
              setState(() {
                if (oldIndex < newIndex) {
                  newIndex -= 1;
                }
                final int item = _items.removeAt(oldIndex);
                _items.insert(newIndex, item);
              });
            },
          ),
        ),
      ),
    ));
  }

  Widget buildItem(context, index) {
    return Container(
      key: Key('$index'),
      decoration: BoxDecoration(
        borderRadius: BorderRadius.circular(10),
        color: Colors.green[200],
      ),
      margin: const EdgeInsets.all(8.0),
      height: 100,
      width: 100,
      child: Center(child: Text('${_items[index]}')),
    );
  }
}

忽略手柄，它们只出现在桌面上，拖放在移动设备上工作。

Answer 2

尝试使用SingleChildScrollView 将Padding 包装在您的Scaffold 中

 SingleChildScrollView(
    scrollDirection: Axis.horizontal,
    child: Padding(),
 )

您可以使用的其他选项是GridView 和ListView。