当我在 TextFormField 中粘贴一些文本以修改/格式化我要粘贴的文本时,我已经尝试了几个星期来放置回调函数。
我使用了带有 SetState 函数的 TextEditingController,用 SetState 上的变量更改了回调函数,但我应该做错了什么。
有时它有效但不是每次都有效。要重现该错误,您可以全选、写入一些字符、粘贴一些文本、剪切、写入、全选并粘贴,大多数情况下我必须进行更改以触发一个事件,然后才能正常工作。 我做错了什么?
提前致谢
import 'dart:convert';
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
// This is the theme of your application.
//
// Try running your application with "flutter run". You'll see the
// application has a blue toolbar. Then, without quitting the app, try
// changing the primarySwatch below to Colors.green and then invoke
// "hot reload" (press "r" in the console where you ran "flutter run",
// or simply save your changes to "hot reload" in a Flutter IDE).
// Notice that the counter didn't reset back to zero; the application
// is not restarted.
primarySwatch: Colors.blue,
// This makes the visual density adapt to the platform that you run
// the app on. For desktop platforms, the controls will be smaller and
// closer together (more dense) than on mobile platforms.
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
// This widget is the home page of your application. It is stateful, meaning
// that it has a State object (defined below) that contains fields that affect
// how it looks.
// This class is the configuration for the state. It holds the values (in this
// case the title) provided by the parent (in this case the App widget) and
// used by the build method of the State. Fields in a Widget subclass are
// always marked "final".
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
TextEditingController orderBoxController = new TextEditingController();
void _incrementCounter() {
setState(() {
// This call to setState tells the Flutter framework that something has
// changed in this State, which causes it to rerun the build method below
// so that the display can reflect the updated values. If we changed
// _counter without calling setState(), then the build method would not be
// called again, and so nothing would appear to happen.
_counter++;
});
}
void _myTextHasChanged(String texto) {
setState(() {
orderBoxController.text = 'i changed';
});
}
@override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
appBar: AppBar(
// Here we take the value from the MyHomePage object that was created by
// the App.build method, and use it to set our appbar title.
title: Text(widget.title),
),
body: Center(
// Center is a layout widget. It takes a single child and positions it
// in the middle of the parent.
child: Column(
// Column is also a layout widget. It takes a list of children and
// arranges them vertically. By default, it sizes itself to fit its
// children horizontally, and tries to be as tall as its parent.
//
// Invoke "debug painting" (press "p" in the console, choose the
// "Toggle Debug Paint" action from the Flutter Inspector in Android
// Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
// to see the wireframe for each widget.
//
// Column has various properties to control how it sizes itself and
// how it positions its children. Here we use mainAxisAlignment to
// center the children vertically; the main axis here is the vertical
// axis because Columns are vertical (the cross axis would be
// horizontal).
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Expanded(
child: new TextFormField(
controller: orderBoxController,
onChanged: _myTextHasChanged,
maxLines: null,
cursorColor: Colors.black,
decoration: new InputDecoration(
border: InputBorder.none,
focusedBorder: InputBorder.none,
enabledBorder: InputBorder.none,
errorBorder: InputBorder.none,
disabledBorder: InputBorder.none,
contentPadding: EdgeInsets.only(
left: 15,
bottom: 11,
top: 11,
right: 15),
hintText: 'Write here'),
style: TextStyle(
fontFamily: 'Segoe UI',
),
),
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
}
我终于在我的 TextFormField 中使用 InputFormatter 解决了我的问题
inputFormatters: [OrderInputFormatter()],
最佳答案
这看起来很奇怪,inputFormatters
不应该对这个问题产生影响。您可以考虑的另一种解决方法是仅在使用 onFieldSubmitted
提交时获取文本。
TextFormField(
onFieldSubmitted: (text) {
debugPrint('Text: $text');
},
...
)
关于flutter - TextFormField 上的粘贴事件不适用于 onChange Flutter,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/61986714/