我有一个文本字段和一个下拉菜单,两者都由 Bloc 控制。我遇到的问题是,一旦选择文本字段,如果用户尝试从下拉菜单中选择某些内容,它就不会放弃焦点。菜单出现,然后立即消失,焦点仍然在文本字段上。
这是一个演示该问题的基本应用程序:
import 'dart:async';
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Textfield Focus Example',
home: HomePage(),
);
}
}
class HomePage extends StatelessWidget {
FormBloc formBloc = FormBloc();
final List<DropdownMenuItem> userMenuItems = ['Bob', 'Frank']
.map((String name) => DropdownMenuItem(
value: name,
child: Text(name),
))
.toList();
@override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
// user - drop down menu
Row(
mainAxisSize: MainAxisSize.min,
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text('To: '),
StreamBuilder<String>(
stream: formBloc.selectedUser,
builder: (context, snapshot) {
return DropdownButton(
items: userMenuItems,
value: snapshot.data,
onChanged: formBloc.selectUser);
}),
],
),
// amount - text field
Row(
mainAxisSize: MainAxisSize.min,
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text('Amount: '),
Container(
width: 100.0,
child: StreamBuilder<double>(
stream: formBloc.billAmount,
builder: (context, snapshot) {
return TextField(
keyboardType: TextInputType.number,
onChanged: formBloc.newBillAmount,
);
})),
],
),
],
),
),
);
}
}
class FormBloc {
StreamController<String> _selectedUserController = StreamController<String>();
Stream<String> get selectedUser =>
_selectedUserController.stream;
Function get selectUser => _selectedUserController.sink.add;
//Amount
StreamController<double> _billAmountController = StreamController<double>();
Stream<double> get billAmount =>
_billAmountController.stream;
void newBillAmount(String amt) =>
_billAmountController.sink.add(double.parse(amt));
void dispose() {
_selectedUserController.close();
_billAmountController.close();
}
}
我是否需要手动为textField声明FocusNode并告诉它何时放弃焦点?或者还有其他原因导致文本字段占据了所有注意力吗?
最佳答案
很抱歉回答晚了,您需要在 DropDownButton Widget 的 onTapListener 中添加以下代码。当您在下拉菜单中选择或单击屏幕外部时,它将删除对文本字段的焦点。谢谢
FocusScope.of(context).requestFocus(new FocusNode());
关于flutter - 选择下拉按钮时文本字段焦点卡住,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/58513576/