当我在Flutter中更改DropDownButton中的项目时，我想更新TextFormField中的文本

Question

我有一个dropDownButton，里面填充了我数据库中的查询。这里有用户，当我选择一个项目时，我想在下面的TextFields中显示所有用户信息。

由于有些信息不应该手工编辑，我想把一些字段作为容器，所以我不能在其中写入，但有些字段应该是TextField，这样我就可以编辑它们。我是新手，所以我仍然不完全理解这一点，而且当我更改dropDownButton时，我找不到在TextFields中加载信息的方法。

这是下面的代码：

class UtilizadorPage extends StatefulWidget {
@override
_UtilizadorPageState createState() => new _UtilizadorPageState();
}
class _UtilizadorPageState extends State<UtilizadorPage> {
Utilizador user = Utilizador();
BDLocal db = BDLocal.instance;
Utilizador? _currentUser;
var txt = TextEditingController();

@override
void initState(){
super.initState();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(
"Utilizadores",
),
),
body: Column(
children: [
Row(
crossAxisAlignment: CrossAxisAlignment.start,
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
FutureBuilder<List<Utilizador>>(
future: user.getUtilizadores(),
builder: (BuildContext context,
AsyncSnapshot<List<Utilizador>> snapshot){
if (!snapshot.hasData) return CircularProgressIndicator();
return DropdownButton<Utilizador>(
alignment: Alignment.center,
items: snapshot.data?.map((util) => DropdownMenuItem<Utilizador>(
child: Text(util.nome),
value: util,
)).toList(),
onChanged:(Utilizador? value) {
setState(() {
_currentUser = value;
});
},
isExpanded: false,
//value: _currentUser,
hint: Text('Select User'),
);
}),
]
),
SizedBox(height: 20.0),
Row(
children: [
_currentUser != null
? Expanded(
child: Column(
children: [
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
Expanded(
flex: 1,
child: Container(
child: InputDecorator(
decoration: InputDecoration(
labelText: "Nome",
floatingLabelBehavior:FloatingLabelBehavior.always,
border: OutlineInputBorder(),
),
child: Text(_currentUser!.nome)
),
),
),
SizedBox(width: 10.0),
Expanded(
flex: 1,
child: Container(
child: InputDecorator(
decoration: InputDecoration(
labelText: "ID na BDNuvem",
floatingLabelBehavior:FloatingLabelBehavior.always,
border: OutlineInputBorder(),
),
child: Text(_currentUser!.id_BDNuvem.toString())
),
),
),
]),
SizedBox(height: 20.0),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
Expanded(
flex: 1,
child: TextFormField(
initialValue: _currentUser!.perfil.toString(),
decoration: InputDecoration(
label: Text("Perfil"),
floatingLabelBehavior:FloatingLabelBehavior.always,
border: OutlineInputBorder(),
),
),
),
SizedBox(width: 10.0),
Expanded(
flex: 1,
child: Container(
child: InputDecorator(
decoration: InputDecoration(
labelText: "Numero de Colaborador",
floatingLabelBehavior:FloatingLabelBehavior.always,
border: OutlineInputBorder(),
),
child: Text(_currentUser!.numero.toString())
),
),
),
],
),
SizedBox(height: 20.0),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
Expanded(
flex: 1,
child: Container(
child: InputDecorator(
decoration: InputDecoration(
labelText: "Nome do Funcionario",
floatingLabelBehavior:FloatingLabelBehavior.always,
border: OutlineInputBorder(),
),
child: Text(_currentUser!.nomeFuncionario)
),
),
),
],
),
SizedBox(height: 20.0),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
Expanded(
flex: 1,
child: Container(
child: InputDecorator(
decoration: InputDecoration(
labelText: "Email",
floatingLabelBehavior:FloatingLabelBehavior.always,
border: OutlineInputBorder(),
),
child: Text(_currentUser!.email)
),
),
),
],
),
SizedBox(height: 20.0),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
Expanded(
flex: 1,
child: Container(
child: InputDecorator(
decoration: InputDecoration(
labelText: "Senha",
floatingLabelBehavior:FloatingLabelBehavior.always,
border: OutlineInputBorder(),
),
child: Text(_currentUser!.senha)
),
),
),
],
),
SizedBox(height: 20.0),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
Expanded(
flex: 1,
child: Container(
child: InputDecorator(
decoration: InputDecoration(
labelText: "Ultima Atualizacao",
floatingLabelBehavior:FloatingLabelBehavior.always,
border: OutlineInputBorder(),
),
child: Text(_currentUser!.ultimaAtualizacao)
),
),
),
SizedBox(width: 10.0),
Expanded(
flex: 1,
child: Container(
child: InputDecorator(
decoration: InputDecoration(
labelText: "Atualizado Por",
floatingLabelBehavior:FloatingLabelBehavior.always,
border: OutlineInputBorder(),
),
child: Text(_currentUser!.atualizadoPor)
),
),
),
],
),
],
),
)
: Text("No User selected"),
],
)
],
),
);
}
}

我现在只有一个textField，因为我还在做实验。我想做的是用我从查询中检索到的信息更新文本的值，例如：_currentUser！。perfil.toString((，它保存一个表示用户类型的字符串

Answer 1

如果您为Textfield分配了一个TextEditingController，您可以通过简单地操作中的值

myTextEditingController.text = "new value";