我想将一行中的 TextFormFields 与其中一个配置了 maxLength 对齐。同样的行为发生在移动和网络上。
Row(
children: [
Expanded(
child: TextFormField(
maxLength: characterLimit,
),
),
Expanded(
child: TextFormField(),
),
]
)
可以理解,maxLength 会增加 TextFormField 底部的空间。由于未对齐,它在没有 maxLength 的 TextFormField 旁边的外观是不可取的。
显示验证器消息会对齐两个 TextFormField。
UsingAlign(alignment: Alignment.top)
什么都不做,因为两个 TextFormField 具有相同的高度,即使其中一个具有 maxLength。使用Padding(padding: EdgeInsets.only(bottom: paddingBottom))
,由于 Padding 给出的偏移量,两个 TextFormField 现在默认具有相同的对齐方式。但是在显示验证器消息时会出现错位。
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
final _subscriptionFormKey = GlobalKey<FormState>();
void _validate() {
if (_subscriptionFormKey.currentState!.validate()) {}
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Form(
key: _subscriptionFormKey,
child: Row(
children: [
Expanded(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: TextFormField(
validator: (message) {
if (message == null || message.isEmpty) {
return 'Empty field';
}
return null;
},
maxLength: 300,
),
),
),
Expanded(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: TextFormField(
validator: (message) {
if (message == null || message.isEmpty) {
return 'Empty field';
}
return null;
},
),
),
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _validate,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
我实现如下。
向 Row 小部件添加了“crossAxisAlignment”参数。
crossAxisAlignment: CrossAxisAlignment.start,
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, @required this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
final _subscriptionFormKey = GlobalKey<FormState>();
void _validate() {
if (_subscriptionFormKey.currentState.validate()) {}
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Form(
key: _subscriptionFormKey,
child: Row(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Expanded(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: TextFormField(
autovalidateMode: AutovalidateMode.always,
validator: (message) {
if (message == null || message.isEmpty) {
return 'Empty field';
}
return null;
},
maxLength: 300,
),
),
),
Expanded(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: TextFormField(
validator: (message) {
if (message == null || message.isEmpty) {
return 'Empty field';
}
return null;
},
),
),
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _validate,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
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