如何为文本字段提供初始值? [英] How do I supply an initial value to a text field?

问题描述

我想为文本字段提供一个初始值，并用一个空值重绘它以清除文本.用Flutter的API做到这一点的最佳方法是什么?

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?

推荐答案

(来自邮件列表.我没有给出这个答案.)

(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'),
        ),
      ],
    );
  }
}

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