📅  最后修改于: 2023-12-03 15:15:09.397000             🧑  作者: Mango
Flutter是一种开源移动应用程序开发框架,可以使用单一代码库构建高性能、高保真的应用程序。掩码检测是一个常见的任务,主要用于验证输入的文本是否符合特定格式的要求。例如,电话号码、日期和邮政编码等。在这个应用程序中,我们将掩码检测与Flutter结合起来,使用户可以轻松输入和验证输入的文本。
本项目旨在提供一个掩码检测应用程序,可以帮助用户验证他们输入的文本是否符合格式要求。该应用程序包含以下步骤:
以下是应用程序的外观示例:
为了让您了解我们的实现,以下是本项目的代码实现。
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
class MaskTextInputFormatter extends TextInputFormatter {
final String mask;
final String separator;
MaskTextInputFormatter({
@required this.mask,
@required this.separator,
});
@override
TextEditingValue formatEditUpdate(
TextEditingValue oldValue, TextEditingValue newValue) {
var value = newValue.text;
var selectionIndex = newValue.selection.end;
var maskIndex = 0;
var result = '';
for (var i = 0; i < value.length && maskIndex < mask.length; i++) {
var char = mask[maskIndex];
if (char == separator) {
result += separator;
maskIndex++;
}
if (maskIndex < mask.length) {
char = mask[maskIndex];
if (char == '0') {
result += value[i];
maskIndex++;
} else {
result += char;
}
}
}
return TextEditingValue(
text: result,
selection: TextSelection.collapsed(
offset: maskIndex < mask.length ? result.length - 1 : result.length),
);
}
}
class MaskValidationPage extends StatefulWidget {
final String mask;
final String title;
MaskValidationPage({@required this.mask, @required this.title});
@override
_MaskValidationPageState createState() => _MaskValidationPageState();
}
class _MaskValidationPageState extends State<MaskValidationPage> {
final _formKey = GlobalKey<FormState>();
String _inputText = '';
bool _showError = false;
String _validateInput(String input) {
if (input.length != widget.mask.length) {
return '输入的内容长度必须符合模式的长度。';
}
for (var i = 0; i < widget.mask.length; i++) {
var char = widget.mask[i];
if (char != '0' && char != input[i]) {
return '输入的内容必须符合模式的要求。';
}
}
return null;
}
void _onInputTextChanged(String value) {
setState(() {
_inputText = value;
_showError = false;
});
}
void _onSubmit() {
if (_formKey.currentState.validate()) {
setState(() {
_showError = false;
});
showDialog(
context: context,
builder: (_) => AlertDialog(
title: Text('输入已确认'),
content: Text('恭喜,您输入的信息符合要求!'),
actions: [
FlatButton(
child: Text('好的'),
onPressed: () => Navigator.of(context).pop(),
),
],
),
);
} else {
setState(() {
_showError = true;
});
}
}
String _applyMask(String input) {
var result = '';
var maskIndex = 0;
for (var i = 0; i < input.length && maskIndex < widget.mask.length; i++) {
var char = widget.mask[maskIndex];
if (char == '0') {
result += input[i];
maskIndex++;
} else {
result += char;
}
}
return result;
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text(widget.title)),
body: Form(
key: _formKey,
autovalidate: _showError,
child: Padding(
padding: EdgeInsets.all(16),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text('请输入:${_applyMask(widget.mask)}', style: TextStyle(fontSize: 18)),
TextFormField(
maxLength: widget.mask.length,
onChanged: _onInputTextChanged,
inputFormatters: [
MaskTextInputFormatter(
mask: widget.mask,
separator: '',
)
],
validator: _validateInput,
keyboardType: TextInputType.number,
),
Padding(
padding: EdgeInsets.only(top: 16),
child: SizedBox(
width: double.infinity,
child: RaisedButton(
onPressed: _onSubmit,
child: Text('确定'),
),
),
),
],
),
),
),
);
}
}
void main() => runApp(MaskValidationApp());
class MaskValidationApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(title: Text('掩码检测')),
body: Padding(
padding: EdgeInsets.all(16),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text('请选择需要输入的文本类型:', style: TextStyle(fontSize: 18)),
SizedBox(height: 16),
RaisedButton(
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (_) => MaskValidationPage(
mask: '000-0000-0000',
title: '输入电话号码',
),
),
);
},
child: Text('电话号码'),
),
SizedBox(height: 16),
RaisedButton(
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (_) => MaskValidationPage(
mask: '00/00/0000',
title: '输入日期',
),
),
);
},
child: Text('日期'),
),
SizedBox(height: 16),
RaisedButton(
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (_) => MaskValidationPage(
mask: '000-0000',
title: '输入邮政编码',
),
),
);
},
child: Text('邮政编码'),
),
],
),
),
),
);
}
}
以上就是我们的Flutter掩码检测应用程序的完整实现。我们使用Flutter的UI框架以及Dart的内置库来实现应用程序的各个组成部分。通过掩码检测,我们可以轻松验证用户输入的文本是否符合指定格式的要求。谢谢!