228
votes

I'd like to supply an initial value to a text field and redraw it with an empty value to clear the text. What's the best approach to do that with Flutter's APIs?

12

12 Answers

152
votes

You can use a TextFormField instead of TextField, and use the initialValue property. for example

TextFormField(initialValue: "I am smart")
151
votes

(From the mailing list. I didn't come up with this answer.)

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'),
        ),
      ],
    );
  }
}
110
votes

You don't have to define a separate variable in the widget scope, just do it inline:

TextField(
  controller: TextEditingController()..text = 'Your initial value',
  onChanged: (text) => {},
)
45
votes

I've seen many ways of doing this on here. However I think this is a little more efficient or at least concise than the other answers.

TextField(
   controller: TextEditingController(text: "Initial Text here"),
)
38
votes

If you are using TextEditingController then set the text to it, like below

TextEditingController _controller = new TextEditingController();


_controller.text = 'your initial text';

final your_text_name = TextFormField(
      autofocus: false,
      controller: _controller,
      decoration: InputDecoration(
        hintText: 'Hint Value',
      ),
    );

and if you are not using any TextEditingController then you can directly use initialValue like below

final last_name = TextFormField(
      autofocus: false,
      initialValue: 'your initial text',
      decoration: InputDecoration(
        hintText: 'Last Name',
      ),
    );

For more reference TextEditingController

22
votes

This can be achieved using TextEditingController.

To have an initial value you can add

TextEditingController _controller = TextEditingController(text: 'initial value');

or

If you are using TextFormField you have a initialValue property there. Which basically provides this initialValue to the widget automatically.

TextFormField(
  initialValue: 'initial value'
)

To clear the text you can use _controller.clear() method.

10
votes

If you want to handle multiple TextInputs as asked by @MRT in the comment to the accepted answer, you can create a function that takes an initial value and returns a TextEditingController like this:

initialValue(val) {
  return TextEditingController(text: val);
}

Then, set this function as the controller for the TextInput and supply its initial value there like this:

controller: initialValue('Some initial value here....')

You can repeat this for the other TextInputs.

6
votes
TextEdittingController _controller = new TextEdittingController(text: "your Text");

or

@override
  void initState() {
    super.initState();
    _Controller.text = "Your Text";
    }
6
votes
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...'),
      ),
    );
  }
}
4
votes

inside class,

  final usernameController = TextEditingController(text: 'bhanuka');

TextField,

   child: new TextField(
        controller: usernameController,
    ...
)
1
votes

You can do all of the above things but, if you want the API to show your data when its's get loaded it shows up like profile page. so here's the code:

TextEditingController _nameController = TextEditingController(); // initialize the controller
 // when API gets the data, do this:
 _nameController.text = response.data.fullName; or _nameController.text = "Apoorv Pandey"

I hope it clears everything. Happy coding!

-1
votes

Easy and Efficient way

Assign controller to your TextFormField or TextField and in initState you can initialise it to the initial value like this

_controller = TextEditingController(text: 'Your initial value');