我用TextFormField收集用户输入,当用户按下FloatingActionButton表示他们已经完成时,我想解散屏幕上的键盘。

如何让键盘自动消失?

import 'package:flutter/material.dart';

class MyHomePage extends StatefulWidget {
  MyHomePageState createState() => new MyHomePageState();
}

class MyHomePageState extends State<MyHomePage> {
  TextEditingController _controller = new TextEditingController();

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(),
      floatingActionButton: new FloatingActionButton(
        child: new Icon(Icons.send),
        onPressed: () {
          setState(() {
            // send message
            // dismiss on screen keyboard here
            _controller.clear();
          });
        },
      ),
      body: new Container(
        alignment: FractionalOffset.center,
        padding: new EdgeInsets.all(20.0),
        child: new TextFormField(
          controller: _controller,
          decoration: new InputDecoration(labelText: 'Example Text'),
        ),
      ),
    );
  }
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      home: new MyHomePage(),
    );
  }
}

void main() {
  runApp(new MyApp());
}

当前回答

如果你使用CustomScrollView,只要放,

keyboardDismissBehavior: ScrollViewKeyboardDismissBehavior.onDrag,

其他回答

注意:这个答案已经过时了。有关Flutter的新版本,请参阅答案。

你可以通过把TextFormField的焦点拿走,并把它给一个未使用的FocusNode来解散键盘:

FocusScope.of(context).requestFocus(FocusNode());

对我来说,上面的App小部件监听器是我发现的最好的方法:

Listener(
  onPointerUp: (_) {
    FocusScopeNode currentFocus = FocusScope.of(context);
    if (!currentFocus.hasPrimaryFocus && currentFocus.focusedChild != null) {
      currentFocus.focusedChild.unfocus();
    }
  },
  child: MaterialApp(
    title: 'Flutter Test App',
    theme: theme,
    ...
  ),
)

在需要时调用此函数

  void hideKeyboard(BuildContext context) {
      FocusScopeNode currentFocus = FocusScope.of(context);
      if (!currentFocus.hasPrimaryFocus && currentFocus.focusedChild != null) {
        FocusManager.instance.primaryFocus?.unfocus();
      }
    }

下面的代码帮助我隐藏键盘

   void initState() {
   SystemChannels.textInput.invokeMethod('TextInput.hide');
   super.initState();
   }

您可以使用FocusNode类中的unfocus()方法。

import 'package:flutter/material.dart';

class MyHomePage extends StatefulWidget {
  MyHomePageState createState() => new MyHomePageState();
}

class MyHomePageState extends State<MyHomePage> {
  TextEditingController _controller = new TextEditingController();
  FocusNode _focusNode = new FocusNode(); //1 - declare and initialize variable

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(),
      floatingActionButton: new FloatingActionButton(
        child: new Icon(Icons.send),
        onPressed: () {
            _focusNode.unfocus(); //3 - call this method here
        },
      ),
      body: new Container(
        alignment: FractionalOffset.center,
        padding: new EdgeInsets.all(20.0),
        child: new TextFormField(
          controller: _controller,
          focusNode: _focusNode, //2 - assign it to your TextFormField
          decoration: new InputDecoration(labelText: 'Example Text'),
        ),
      ),
    );
  }
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      home: new MyHomePage(),
    );
  }
}

void main() {
  runApp(new MyApp());
}