Question

您好，我只是想在列表项的右侧包含一个切换按钮。这样做时，我最终得到了这个 BoxConstraints 强制无限宽度错误。作为一个完整的初学者，有人可以让我知道这是什么意思吗？我必须对代码进行哪些更改才能消除此错误？

import 'package:attendee/constants.dart';
import 'package:flutter/material.dart';
import 'package:attendee/models/userdeails.dart';

class userdetailsTile extends StatelessWidget {
  final userdetails userdetail;
  userdetailsTile({this.userdetail});

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: EdgeInsets.only(top: 8.0),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
        crossAxisAlignment: CrossAxisAlignment.center,
        children: <Widget>[
          Card(
            //margin: EdgeInsets.fromLTRB(20.0, 6.0, 20.0, 0.0),
            child: GestureDetector(
              child: ListTile(
                leading: CircleAvatar(
                  radius: 25.0,
                  backgroundColor: Colors.lightGreen,
                ),
                title: Text(userdetail.fullname),
              ),
            ),
          ),
          Switch(
            value: present,
            onChanged: (value) {
              //setState(() {
              present = value;
              print(present);
              //});
            },
            activeTrackColor: Colors.lightGreenAccent,
            activeColor: Colors.green,
          ),
          //),
        ],
      ),
    );
  }
}

Answer 1

请检查以下解决方案。

解决方案 1

 return Material(child: Padding(
    padding: EdgeInsets.only(top: 8.0),
    child: ListTile(
            leading: CircleAvatar(
              radius: 25.0,
              backgroundColor: Colors.lightGreen,
            ),
            title: Text(userdetail.fullname),
            trailing: Switch(
              value: present,
              onChanged: (value) {
                //setState(() {
                present = value;
                print(present);
                //});
              },
              activeTrackColor: Colors.lightGreenAccent,
              activeColor: Colors.green,
            ),
          ),
    ),
  );

解决方案 2

 return Material(child: 
   Padding(
    padding: EdgeInsets.only(top: 8.0),
    child: Row(
      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
      crossAxisAlignment: CrossAxisAlignment.center,
      children: <Widget>[
        Expanded(
          child: Card(
            //margin: EdgeInsets.fromLTRB(20.0, 6.0, 20.0, 0.0),
            child: Row(
              children: [
                CircleAvatar(
                  radius: 25.0,
                  backgroundColor: Colors.lightGreen,
                ), Text(userdetail.fullname)
              ],
            ),
          ),
        ),
        Switch(
          value: present,
          onChanged: (value) {
            //setState(() {
            present = value;
            print(present);
            //});
          },
          activeTrackColor: Colors.lightGreenAccent,
          activeColor: Colors.green,
        ),
        //),
      ],
    ),
   ),
  );

如何解决 BoxConstraints 在颤动中强制无限宽度异常？

1 个答案: