我想为文本字段提供一个初始值,并重新绘制一个空值以清除文本。用Flutter的api实现这一点的最佳方法是什么?
当前回答
TextEdittingController _controller = new TextEdittingController(text: "your Text");
or
@override
void initState() {
super.initState();
_Controller.text = "Your Text";
}
其他回答
如果你正在使用TextEditingController,然后设置文本为它,如下所示
TextEditingController _controller = new TextEditingController();
_controller.text = 'your initial text';
final your_text_name = TextFormField(
autofocus: false,
controller: _controller,
decoration: InputDecoration(
hintText: 'Hint Value',
),
);
如果你不使用任何TextEditingController,那么你可以直接使用initialValue如下
final last_name = TextFormField(
autofocus: false,
initialValue: 'your initial text',
decoration: InputDecoration(
hintText: 'Last Name',
),
);
更多参考TextEditingController
(来自邮件列表。这个答案不是我想出来的。)
class _FooState extends State<Foo> {
TextEditingController _controller;
@override
void initState() {
super.initState();
_controller = new TextEditingController(text: 'Initial value');
}
@override
Widget build(BuildContext context) {
return new Column(
children: <Widget>[
new TextField(
// The TextField is first built, the controller has some initial text,
// which the TextField shows. As the user edits, the text property of
// the controller is updated.
controller: _controller,
),
new RaisedButton(
onPressed: () {
// You can also use the controller to manipuate what is shown in the
// text field. For example, the clear() method removes all the text
// from the text field.
_controller.clear();
},
child: new Text('CLEAR'),
),
],
);
}
}
你可以使用TextFormField代替TextField,并使用initialValue属性。例如
TextFormField(initialValue: "I am smart")
我在这里见过很多方法。然而,我认为这比其他答案更有效或至少更简洁。
TextField(
controller: TextEditingController(text: "Initial Text here"),
)
class _YourClassState extends State<YourClass> {
TextEditingController _controller = TextEditingController();
@override
void initState() {
super.initState();
_controller.text = 'Your message';
}
@override
Widget build(BuildContext context) {
return Container(
color: Colors.white,
child: TextFormField(
controller: _controller,
decoration: InputDecoration(labelText: 'Send message...'),
),
);
}
}