不能在标准ListView小组件上滚动，总是超额渲染150px。

Question

ListView根本无法滚动。错误说问题出在main.dart文件里，而不是我正在做的模块里，但是是模块溢出了。

试了多种方法。

• primary: false,physics: const AlwaysScrollableScrollPhysics(),controller: _controller
• Flutter开发文档中关于制作列表视图的内容。
• 关于使列表浏览量的中等职位
• 无数堆栈溢出的Q

这是我的代码。

import 'package:flutter/material.dart';

class Listicle extends StatefulWidget {
  @override
  ListicleState createState() => ListicleState();
}

class ListicleState extends State<Listicle> {
  final List<String> entries = <String>['A', 'B', 'C', 'D', 'E', 'F'];
  final List<int> colorCodes = <int>[600, 500, 100, 600, 500, 100];

  ScrollController _controller = new ScrollController();

  @override
  Widget build(BuildContext context) {
    return Container(
      child: ListView.builder(
        primary: false,
        physics: const AlwaysScrollableScrollPhysics(),
        controller: _controller,
        shrinkWrap: true,
        padding: const EdgeInsets.all(8),
        itemCount: entries.length,
        itemBuilder: (BuildContext context, int index) {
          return Container(
            height: 100,
            color: Colors.amber[colorCodes[index]],
            child: Center(child: Text('Entry ${entries[index]}')),
          );
        }
      )
    );
  }
}

这是个错误

════════ Exception caught by rendering library ═════════════════════════════════════════════════════
The following assertion was thrown during layout:
A RenderFlex overflowed by 150 pixels on the bottom.

The relevant error-causing widget was: 
  Column file:///Users/christopher/AndroidStudioProjects/test_app/lib/main.dart:76:13
The overflowing RenderFlex has an orientation of Axis.vertical.
The edge of the RenderFlex that is overflowing has been marked in the rendering with a yellow and black striped pattern. This is usually caused by the contents being too big for the RenderFlex.

Consider applying a flex factor (e.g. using an Expanded widget) to force the children of the RenderFlex to fit within the available space instead of being sized to their natural size.
This is considered an error condition because it indicates that there is content that cannot be seen. If the content is legitimately bigger than the available space, consider clipping it with a ClipRect widget before putting it in the flex, or using a scrollable container rather than a Flex, like a ListView.

The specific RenderFlex in question is: RenderFlex#c9341 relayoutBoundary=up1 OVERFLOWING
...  needs compositing
...  parentData: offset=Offset(0.0, 80.0); id=_ScaffoldSlot.body (can use size)
...  constraints: BoxConstraints(0.0<=w<=392.7, 0.0<=h<=679.3)
...  size: Size(392.7, 679.3)
...  direction: vertical
...  mainAxisAlignment: start
...  mainAxisSize: max
...  crossAxisAlignment: center
...  verticalDirection: down
◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤◢◤
════════════════════════════════════════════════════════════════════════════════════════════════════

我是 很 新到flutterdart（昨天才开始的），这让我已经很困惑了。

这是一个快照。https:/i.stack.imgur.comqlDMZ.png。

Answer 1

这样就可以了。

import 'package:flutter/material.dart';

final Color darkBlue = Color.fromARGB(255, 18, 32, 47);

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData.dark().copyWith(scaffoldBackgroundColor: darkBlue),
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Center(
          child: Listicle(),
        ),
      ),
    );
  }
}

class Listicle extends StatefulWidget {
  @override
  ListicleState createState() => ListicleState();
}

class ListicleState extends State<Listicle> {
  final List<String> entries = <String>['A', 'B', 'C', 'D', 'E', 'F','G','H'];
  final List<int> colorCodes = <int>[600, 500, 100, 600, 500, 100,100,100];

 @override
  Widget build(BuildContext context) {
    return Container(
      child: ListView.builder(
        primary: false,
        shrinkWrap: true,
        padding: const EdgeInsets.all(8),
        itemCount: entries.length,
        itemBuilder: (BuildContext context, int index) {
          return Container(
            height: 100,
            color: Colors.amber[colorCodes[index]],
            child: Center(child: Text('Entry ${entries[index]}')),
          );
        }
      )
    );
  }
}

Answer 2

错误发生的原因是... ListView 膨胀到主轴方向的最大尺寸。

解决办法。

正如 @rocigno-medeiros 在评论中所说的那样

通过将您的代码封装在 Scaffold 使其成功，因为 Scaffold 限制高度 ListView.

class Listicle extends StatefulWidget {
  @override
  ListicleState createState() => ListicleState();
}

class ListicleState extends State<Listicle> {
  final List<String> entries = <String>['A', 'B', 'C', 'D', 'E', 'F'];
  final List<int> colorCodes = <int>[600, 500, 100, 600, 500, 100];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Container(
        child: ListView.builder(
          primary: false,
          physics: AlwaysScrollableScrollPhysics(),
          shrinkWrap: true,
          padding: const EdgeInsets.all(8),
          itemCount: entries.length,
          itemBuilder: (BuildContext context, int index) {
            return Container(
              height: 100,
              color: Colors.amber[colorCodes[index]],
              child: Center(child: Text('Entry ${entries[index]}')),
            );
          },
        ),
      ),
    );
  }
}

如果你想要默认的滚动行为，也不需要额外的滚动控制器。

更多的信息与一个伟大的答案 此处.