Flutter Form正确使用方法【可正确获取提交的表单数据】

import 'package:flutter/material.dart';

void main() => runApp(new HomePage());

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => new _HomePageState();
}

class _HomePageState extends State<HomePage> {
  GlobalKey<FormState> _formKey = new GlobalKey<FormState>();

  String _name;

  String _password;

  void _forSubmitted() {
    var _form = _formKey.currentState;

    if (_form.validate()) {
      _form.save();
      print(_name);
      print(_password);
    }
  }

  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return new MaterialApp(
      title: 'Flutter data',
      home: new Scaffold(
        appBar: new AppBar(
          title: new Text('Flutter Form正确使用方法'),
        ),
        floatingActionButton: new FloatingActionButton(
          onPressed: _forSubmitted,
          child: new Text('提交'),
        ),
        body: new Container(
          padding: const EdgeInsets.all(16.0),
          child: new Form(
            key: _formKey,
            child: new Column(
              children: <Widget>[
                new TextFormField(
                  decoration: new InputDecoration(
                    labelText: 'Your Name',
                  ),
                  onSaved: (val) {
                    _name = val;
                  },
                ),
                new TextFormField(
                  decoration: new InputDecoration(
                    labelText: 'Password',
                  ),
                  obscureText: true,
                  validator: (val) {
                    return val.length < 4 ? "密码长度错误" : null;
                  },
                  onSaved: (val) {
                    _password = val;
                  },
                ),
                Padding(
                  padding: const EdgeInsets.only(top: 28.0),
                  child: Row(
                    children: <Widget>[
                      Expanded(
                        child: RaisedButton(
                            padding: EdgeInsets.all(15.0),
                            child: Text('登录'),
                            color: Colors.blue,
                            textColor: Colors.white,
                            onPressed:this._forSubmitted,
                        )
                      )
                    ]
                  ),
                )
              ],
            ),
          ),
        ),
      ),
    );
  }
}