Как добавить кнопку очистки в виджет TextField
Есть ли правильный способ добавить кнопку очистки в виджет TextField во флаттере?
как эта картина в руководящих принципах материнского дизайна: 
То, что я нашел, это установить четкую иконку в суффиксе InputDecorationIcon. Это правильный путь?
20 ответов
Выход:
Создать переменную
var _controller = TextEditingController();
И ваш TextField:
TextField(
controller: _controller,
decoration: InputDecoration(
hintText: "Enter a message",
suffixIcon: IconButton(
onPressed: () => _controller.clear(),
icon: Icon(Icons.clear),
),
),
)
Container(
margin: EdgeInsets.only(left: 16.0),
child: TextFormField(
controller: _username,
decoration: InputDecoration(
hintText: '请输入工号',
filled: true,
prefixIcon: Icon(
Icons.account_box,
size: 28.0,
),
suffixIcon: IconButton(
icon: Icon(Icons.remove),
onPressed: () {
debugPrint('222');
})),
),
),
использовать iconButton
Попробуй это -
final TextEditingController _controller = new TextEditingController();
new Stack(
alignment: const Alignment(1.0, 1.0),
children: <Widget>[
new TextField(controller: _controller,),
new FlatButton(
onPressed: () {
_controller.clear();
},
child: new Icon(Icons.clear))
]
)
Вот еще один ответ, немного расширивший ответ @Vilokan Lab, который на самом деле не делал этого для меня, поскольку FlatButton имеет минимальную ширину 88,0, и, таким образом, кнопка очистки вообще не выровнена по правому краю с TextField.
Итак, я сделал свой собственный класс кнопок и применил его с помощью стека, вот мой процесс:
Класс кнопки:
class CircleIconButton extends StatelessWidget {
final double size;
final Function onPressed;
final IconData icon;
CircleIconButton({this.size = 30.0, this.icon = Icons.clear, this.onPressed});
@override
Widget build(BuildContext context) {
return InkWell(
onTap: this.onPressed,
child: SizedBox(
width: size,
height: size,
child: Stack(
alignment: Alignment(0.0, 0.0), // all centered
children: <Widget>[
Container(
width: size,
height: size,
decoration: BoxDecoration(
shape: BoxShape.circle, color: Colors.grey[300]),
),
Icon(
icon,
size: size * 0.6, // 60% width for icon
)
],
)));
}
}
Затем примените так, как InputDecoration в ваш TextField:
var myTextField = TextField(
controller: _textController,
decoration: InputDecoration(
hintText: "Caption",
suffixIcon: CircleIconButton(
onPressed: () {
this.setState(() {
_textController.clear();
});
},
)),
},
);
Чтобы получить это:
Невыделенное состояние
Выделенное / выбранное состояние.
Обратите внимание, эта окраска предоставляется бесплатно при использовании suffixIcon,
Обратите внимание, что вы также можете поместить его в свой TextField следующим образом, но вы не получите автоцвет, который вы получите при использовании suffixIcon:
var myTextFieldView = Stack(
alignment: Alignment(1.0,0.0), // right & center
children: <Widget>[
TextField(
controller: _textController,
decoration: InputDecoration(hintText: "Caption"),
),
Positioned(
child: CircleIconButton(
onPressed: () {
this.setState(() {
_textController.clear();
});
},
),
),
],
);
Поиск TextField со значком и кнопкой очистки
import 'package:flutter/material.dart';
class SearchTextField extends StatefulWidget{
@override
State<StatefulWidget> createState() {
// TODO: implement createState
return new SearchTextFieldState();
}
}
class SearchTextFieldState extends State<SearchTextField>{
final TextEditingController _textController = new TextEditingController();
@override
Widget build(BuildContext context) {
// TODO: implement build
return new Row(children: <Widget>[
new Icon(Icons.search, color: _textController.text.length>0?Colors.lightBlueAccent:Colors.grey,),
new SizedBox(width: 10.0,),
new Expanded(child: new Stack(
alignment: const Alignment(1.0, 1.0),
children: <Widget>[
new TextField(
decoration: InputDecoration(hintText: 'Search'),
onChanged: (text){
setState(() {
print(text);
});
},
controller: _textController,),
_textController.text.length>0?new IconButton(icon: new Icon(Icons.clear), onPressed: () {
setState(() {
_textController.clear();
});
}):new Container(height: 0.0,)
]
),),
],);
}
}
TextEditingController используется для проверки текущего состояния текста, где мы можем решить, можем ли мы показать значок отмены или нет, в зависимости от доступности текста.
var _usernameController = TextEditingController();
@override
Widget build(BuildContext context) {
return Scaffold(
body: Padding(
padding: const EdgeInsets.all(16.0),
child: Center(
child: TextField(
controller: _usernameController,
onChanged: (text) {
setState(() {});
},
decoration: InputDecoration(
labelText: 'Username',
suffixIcon: _usernameController.text.length > 0
? IconButton(
onPressed: () {
_usernameController.clear();
setState(() {});
},
icon: Icon(Icons.cancel, color: Colors.grey))
: null),
),
),
),
);
}
Выход:
TextFormField(
controller:_controller
decoration: InputDecoration(
suffixIcon: IconButton(
onPressed: (){
_controller.clear();
},
icon: Icon(
Icons.keyboard,
color: Colors.blue,
),
),
),
)
TextFormField(
controller:_controller
decoration: InputDecoration(
suffixIcon: IconButton(
onPressed: (){
_controller.clear();
},
icon: Icon(
Icons.keyboard,
color: Colors.blue,
),
),
),
)
Вот фрагмент моего работающего кода.
Что он делает: показывать кнопку очистки, только если значение текстового поля не пусто
class _MyTextFieldState extends State<MyTextField> {
TextEditingController _textController;
bool _wasEmpty;
@override
void initState() {
super.initState();
_textController = TextEditingController(text: widget.initialValue);
_wasEmpty = _textController.text.isEmpty;
_textController.addListener(() {
if (_wasEmpty != _textController.text.isEmpty) {
setState(() => {_wasEmpty = _textController.text.isEmpty});
}
});
}
@override
void dispose() {
_textController.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return TextFormField(
controller: _textController,
decoration: InputDecoration(
labelText: widget.label,
suffixIcon: _textController.text.isNotEmpty
? Padding(
padding: const EdgeInsetsDirectional.only(start: 12.0),
child: IconButton(
iconSize: 16.0,
icon: Icon(Icons.cancel, color: Colors.grey,),
onPressed: () {
setState(() {
_textController.clear();
});
},
),
)
: null,
),);
...
suffixIcon: IconButton(
icon: Icon(
Icons.cancel,
),
onPressed: () {
_controllerx.text = '';
),
Не хотел идти по маршруту StatefulWidget. Вот пример использования TextEditingController и StatelessWidget (когда провайдеры отправляют обновления). Держу контроллер в статическом поле.
class _SearchBar extends StatelessWidget {
static var _controller = TextEditingController();
@override
Widget build(BuildContext context) {
var dictionary = Provider.of<Dictionary>(context);
return TextField(
controller: _controller,
autofocus: true,
onChanged: (text) {
dictionary.lookupWord = text;
},
style: TextStyle(fontSize: 20.0),
decoration: InputDecoration(
border: InputBorder.none,
hintText: 'Search',
suffix: GestureDetector(
onTap: () {
dictionary.lookupWord = '';
_controller.clear();
},
child: Text('x'),
)));
}
}
Добавить значок внутри текстового поля. Вы должны использовать SuffixIcon или prefixIcon внутри оформления ввода.
TextFormField(
autofocus: false,
obscureText: true,
decoration: InputDecoration(
labelText: 'Password',
suffixIcon: Icon(
Icons.clear,
size: 20.0,
),
border: OutlineInputBorder(
borderRadius: BorderRadius.all(Radius.circular(0.0)),
),
hintText: 'Enter Password',
contentPadding: EdgeInsets.all(10.0),
),
);
Если вам нужен готовый к использованию виджет, который вы можете просто поместить в файл, а затем иметь многоразовый элемент, который вы можете использовать везде, вставив ClearableTextField(), используйте этот фрагмент кода:
import 'package:flutter/material.dart';
class ClearableTexfield extends StatefulWidget {
ClearableTexfield({
Key key,
this.controller,
this.hintText = 'Enter text'
}) : super(key: key);
final TextEditingController controller;
final String hintText;
@override
State<StatefulWidget> createState() {
return _ClearableTextfieldState();
}
}
class _ClearableTextfieldState extends State<ClearableTexfield> {
bool _showClearButton = false;
@override
void initState() {
super.initState();
widget.controller.addListener(() {
setState(() {
_showClearButton = widget.controller.text.length > 0;
});
});
}
@override
Widget build(BuildContext context) {
return TextField(
controller: widget.controller,
decoration: InputDecoration(
hintText: widget.hintText,
suffixIcon: _getClearButton(),
),
);
}
Widget _getClearButton() {
if (!_showClearButton) {
return null;
}
return IconButton(
onPressed: () => widget.controller.clear(),
icon: Icon(Icons.clear),
);
}
}
Дополнительные объяснения можно найти на этой странице:
https://www.flutterclutter.dev/flutter/tutorials/text-field-with-clear-button/2020/104/
Он также основан на IconButton, но имеет то преимущество, что кнопка очистки отображается только при наличии текста внутри текстового поля.
Выглядит так:
Вы также можете использовать TextFormField. Сначала создайте ключ формы.
final _formKeylogin = GlobalKey<FormState>();
Form(key: _formKeylogin,
child: Column(
children: [
Container(
margin: EdgeInsets.all(20.0),
child: TextFormField(
style: TextStyle(color: WHITE),
textInputAction: TextInputAction.next,
onChanged: (companyName) {
},
validator: (companyName) {
if (companyName.isEmpty) {
return 'Please enter company Name';
} else {
return null;
}
},
),
И в методе OnTap или onPress.
_formKeylogin.currentState.reset();
(Aug 19, 2021) Robust solution based on the code written by the Flutter team
Here is a fully reusuable with maximum configuration, most of the code for this clearable text field here is from the commits on Apr 1, 2021 of the Flutter team for the built-in . The accepts the same params as and works similarly to the built-in .
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
// A [TextFormField] with a clear button
class ClearableTextFormField extends FormField<String> {
/// Creates a [FormField] that contains a [TextField].
///
/// When a [controller] is specified, [initialValue] must be null (the
/// default). If [controller] is null, then a [TextEditingController]
/// will be constructed automatically and its `text` will be initialized
/// to [initialValue] or the empty string.
///
/// For documentation about the various parameters, see the [TextField] class
/// and [new TextField], the constructor.
ClearableTextFormField({
Key? key,
this.controller,
String? initialValue,
FocusNode? focusNode,
InputDecoration decoration = const InputDecoration(),
TextInputType? keyboardType,
TextCapitalization textCapitalization = TextCapitalization.none,
TextInputAction? textInputAction,
TextStyle? style,
StrutStyle? strutStyle,
TextDirection? textDirection,
TextAlign textAlign = TextAlign.start,
TextAlignVertical? textAlignVertical,
bool autofocus = false,
bool readOnly = false,
ToolbarOptions? toolbarOptions,
bool? showCursor,
String obscuringCharacter = '•',
bool obscureText = false,
bool autocorrect = true,
SmartDashesType? smartDashesType,
SmartQuotesType? smartQuotesType,
bool enableSuggestions = true,
MaxLengthEnforcement? maxLengthEnforcement,
int? maxLines = 1,
int? minLines,
bool expands = false,
int? maxLength,
ValueChanged<String>? onChanged,
GestureTapCallback? onTap,
VoidCallback? onEditingComplete,
ValueChanged<String>? onFieldSubmitted,
FormFieldSetter<String>? onSaved,
FormFieldValidator<String>? validator,
List<TextInputFormatter>? inputFormatters,
bool? enabled,
double cursorWidth = 2.0,
double? cursorHeight,
Radius? cursorRadius,
Color? cursorColor,
Brightness? keyboardAppearance,
EdgeInsets scrollPadding = const EdgeInsets.all(20.0),
bool enableInteractiveSelection = true,
TextSelectionControls? selectionControls,
InputCounterWidgetBuilder? buildCounter,
ScrollPhysics? scrollPhysics,
Iterable<String>? autofillHints,
AutovalidateMode? autovalidateMode,
ScrollController? scrollController,
// Features
this.resetIcon = const Icon(Icons.close),
}) : assert(initialValue == null || controller == null),
assert(obscuringCharacter.length == 1),
assert(
maxLengthEnforcement == null,
'maxLengthEnforced is deprecated, use only maxLengthEnforcement',
),
assert(maxLines == null || maxLines > 0),
assert(minLines == null || minLines > 0),
assert(
(maxLines == null) || (minLines == null) || (maxLines >= minLines),
"minLines can't be greater than maxLines",
),
assert(
!expands || (maxLines == null && minLines == null),
'minLines and maxLines must be null when expands is true.',
),
assert(!obscureText || maxLines == 1,
'Obscured fields cannot be multiline.'),
assert(maxLength == null || maxLength > 0),
super(
key: key,
initialValue:
controller != null ? controller.text : (initialValue ?? ''),
onSaved: onSaved,
validator: validator,
enabled: enabled ?? true,
autovalidateMode: autovalidateMode ?? AutovalidateMode.disabled,
builder: (FormFieldState<String> field) {
final _ClearableTextFormFieldState state =
field as _ClearableTextFormFieldState;
final InputDecoration effectiveDecoration = decoration
.applyDefaults(Theme.of(field.context).inputDecorationTheme);
void onChangedHandler(String value) {
field.didChange(value);
if (onChanged != null) onChanged(value);
}
return Focus(
onFocusChange: (hasFocus) => state.setHasFocus(hasFocus),
child: TextField(
controller: state._effectiveController,
focusNode: focusNode,
decoration: effectiveDecoration.copyWith(
errorText: field.errorText,
suffixIcon:
((field.value?.length ?? -1) > 0 && state.hasFocus)
? IconButton(
icon: resetIcon,
onPressed: () => state.clear(),
color: Theme.of(state.context).hintColor,
)
: null,
),
keyboardType: keyboardType,
textInputAction: textInputAction,
style: style,
strutStyle: strutStyle,
textAlign: textAlign,
textAlignVertical: textAlignVertical,
textDirection: textDirection,
textCapitalization: textCapitalization,
autofocus: autofocus,
toolbarOptions: toolbarOptions,
readOnly: readOnly,
showCursor: showCursor,
obscuringCharacter: obscuringCharacter,
obscureText: obscureText,
autocorrect: autocorrect,
smartDashesType: smartDashesType ??
(obscureText
? SmartDashesType.disabled
: SmartDashesType.enabled),
smartQuotesType: smartQuotesType ??
(obscureText
? SmartQuotesType.disabled
: SmartQuotesType.enabled),
enableSuggestions: enableSuggestions,
maxLengthEnforcement: maxLengthEnforcement,
maxLines: maxLines,
minLines: minLines,
expands: expands,
maxLength: maxLength,
onChanged: onChangedHandler,
onTap: onTap,
onEditingComplete: onEditingComplete,
onSubmitted: onFieldSubmitted,
inputFormatters: inputFormatters,
enabled: enabled ?? true,
cursorWidth: cursorWidth,
cursorHeight: cursorHeight,
cursorRadius: cursorRadius,
cursorColor: cursorColor,
scrollPadding: scrollPadding,
scrollPhysics: scrollPhysics,
keyboardAppearance: keyboardAppearance,
enableInteractiveSelection: enableInteractiveSelection,
selectionControls: selectionControls,
buildCounter: buildCounter,
autofillHints: autofillHints,
scrollController: scrollController,
),
);
},
);
/// Controls the text being edited.
///
/// If null, this widget will create its own [TextEditingController] and
/// initialize its [TextEditingController.text] with [initialValue].
final TextEditingController? controller;
final Icon resetIcon;
@override
_ClearableTextFormFieldState createState() => _ClearableTextFormFieldState();
}
class _ClearableTextFormFieldState extends FormFieldState<String> {
TextEditingController? _controller;
bool hasFocus = false;
TextEditingController get _effectiveController =>
widget.controller ?? _controller!;
@override
ClearableTextFormField get widget => super.widget as ClearableTextFormField;
@override
void initState() {
super.initState();
if (widget.controller == null)
_controller = TextEditingController(text: widget.initialValue);
else
widget.controller!.addListener(_handleControllerChanged);
}
@override
void didUpdateWidget(ClearableTextFormField oldWidget) {
super.didUpdateWidget(oldWidget);
if (widget.controller != oldWidget.controller) {
oldWidget.controller?.removeListener(_handleControllerChanged);
widget.controller?.addListener(_handleControllerChanged);
if (oldWidget.controller != null && widget.controller == null)
_controller =
TextEditingController.fromValue(oldWidget.controller!.value);
if (widget.controller != null) {
setValue(widget.controller!.text);
if (oldWidget.controller == null) _controller = null;
}
}
}
@override
void dispose() {
widget.controller?.removeListener(_handleControllerChanged);
super.dispose();
}
@override
void didChange(String? value) {
super.didChange(value);
if (_effectiveController.text != value)
_effectiveController.text = value ?? '';
}
@override
void reset() {
// setState will be called in the superclass, so even though state is being
// manipulated, no setState call is needed here.
_effectiveController.text = widget.initialValue ?? '';
super.reset();
}
void setHasFocus(bool b) => setState(() => hasFocus = b);
void _handleControllerChanged() {
// Suppress changes that originated from within this class.
//
// In the case where a controller has been passed in to this widget, we
// register this change listener. In these cases, we'll also receive change
// notifications for changes originating from within this class -- for
// example, the reset() method. In such cases, the FormField value will
// already have been set.
if (_effectiveController.text != value)
didChange(_effectiveController.text);
}
/// Invoked by the clear suffix icon to clear everything in the [FormField]
void clear() {
WidgetsBinding.instance!.addPostFrameCallback((_) {
_effectiveController.clear();
didChange(null);
});
}
}
Read more about the assert statement in the Dart language doc.
Below are the explanations for the additional code added to the built-in
Optional
resetIcon param for the
ClearableTextFormField
🚀 Additional code inside
_ClearableTextFormFieldState:
/// Invoked by the clear suffix icon to clear everything in the [FormField]
void clear() {
WidgetsBinding.instance!.addPostFrameCallback((_) {
_effectiveController.clear();
didChange(null);
});
}
addPostFrameCallback() ensures the passed-in function is only called on Widget build complete (when the
TextFormField has been fully built and rendered on the screen). U can read more about it in this thread.
The following state and setState allows u to keep track of the focus change in (when the field is focused or unfocused):
bool hasFocus = false;
void setHasFocus(bool b) => setState(() => hasFocus = b);
🚀 Additional code inside the
builder method of the extended
FormField<String> (the
super() parts):
Hide the clear button when the field's value is empty or
null:
suffixIcon:
((field.value?.length ?? -1) > 0 && state.hasFocus)
? IconButton(
icon: resetIcon,
onPressed: () => state.clear(),
color: Theme.of(state.context).hintColor,
)
: null,
Rebuild the
TextField on focus and unfocus to show and hide the clear button:
Focus(
onFocusChange: (hasFocus) => state.setHasFocus(hasFocus),
child: TextField(// more code here...),
)
Чтобы очистить кнопку, когда ввод не пустой и с фокусом.
Создайте переменную контроллера:
//Clear inputs
final _nameInputcontroller = TextEditingController();
Создайте FocusNode:
late FocusNode focusNodeNameInput;
@override
void initState() {
super.initState();
//FocusNode for all inputs
focusNodeNameInput = FocusNode();
focusNodeNameInput.addListener(() {
setState(() {});
});
}
@override
void dispose() {
// Clean up the focus node when the Form is disposed.
focusNodeNameInput.dispose();
super.dispose();
}
И TextFormField:
TextFormField(
controller: _nameInputcontroller,
focusNode: focusNodeNameInput,
decoration: InputDecoration(
labelText: LocaleKeys.name.tr(),
labelStyle: TextStyle(
color: focusNodeNameInput.hasFocus ? AppColors.MAIN_COLOR : null,
),
focusedBorder: const UnderlineInputBorder(
borderSide: BorderSide(
color: AppColors.MAIN_COLOR,
),
),
suffixIcon: _nameInputcontroller.text.isNotEmpty || focusNodeNameInput.hasFocus
? IconButton(
onPressed: _nameInputcontroller.clear,
icon: const Icon(
Icons.clear,
color: AppColors.MAIN_COLOR,
),
) : null,
),
),
Используя пакет flutter_hooks , это может выглядеть так
class SearchField extends HookWidget {
const SearchField({
required this.controller,
});
final TextEditingController controller;
@override
Widget build(BuildContext context) {
final StreamController<String> sc = useStreamController<String>();
const OutlineInputBorder border = OutlineInputBorder(
borderSide: BorderSide(
width: 1,
color: Color(0xFFD9D9D9),
),
);
return TextField(
controller: controller,
onChanged: sc.add,
decoration: InputDecoration(
prefixIcon: const Icon(Icons.search),
hintText: 'Search',
enabledBorder: border,
focusedBorder: border,
suffixIcon: StreamBuilder<String>(
stream: sc.stream,
initialData: '',
builder: (BuildContext context, AsyncSnapshot<String> snapshot) {
if (snapshot.data!.isEmpty) return const SizedBox();
return IconButton(
icon: const Icon(Icons.cancel),
onPressed: () => controller.clear(),
);
},
),
),
);
}
}
IconButton(
icon: Icon(Icons.clear_all),
tooltip: 'Close',
onPressed: () {
},
)
Для приложения Android используйте этот код
Макет (XML)
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="16dp"
android:orientation="vertical">
<SearchView
android:id="@+id/searchView"
android:layout_width="wrap_content"
android:elevation="2dp"
android:background="#fff"
android:layout_height="wrap_content">
</SearchView>
</LinearLayout>
Теперь Java-код для функциональности
public class MainActivity extends AppCompatActivity{
SearchView searchView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.searchview_android_example);
searchView=(SearchView) findViewById(R.id.searchView);
searchView.setQueryHint("Search View");
searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
@Override
public boolean onQueryTextSubmit(String query) {
Toast.makeText(getBaseContext(), query, Toast.LENGTH_LONG).show();
return false;
}
@Override
public boolean onQueryTextChange(String newText) {
Toast.makeText(getBaseContext(), newText, Toast.LENGTH_LONG).show();
return false;
}
});
}
}
Если вы создаете сайт и нуждаетесь в таком функционале, используйте **
<input type="search"/>
** он предоставит вам крестик для удаления текста.