Question

我正在寻找一种方法来克服颤振Textfiend上/下键的行为。

当前，它们将光标移动到文本字段的开头或结尾。

我想更改此行为。我乐于接受任何可能性。

我研究了用RawKeyboardListener包装文本字段，但是向上/向下键事件仍然落入文本字段。

Answer 1

星期六有趣的问题，花了我的空闲时间:) 发现我们可以为任何键获取UP和DOWN事件。下面的示例在按向上箭头时将光标向后移动3个字母。

代码

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: KeyboardListener(),
    );
  }
}

class KeyboardListener extends StatefulWidget {
  KeyboardListener();

  @override
  _RawKeyboardListenerState createState() => _RawKeyboardListenerState();
}

class _RawKeyboardListenerState extends State<KeyboardListener> {
  TextEditingController _controller = TextEditingController();
  FocusNode _textNode = FocusNode();
  String _keyPressed = 'Key pressed code: ';

  @override
  initState() {
    super.initState();
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    FocusScope.of(context).requestFocus(_textNode);
    return Scaffold(
      appBar: AppBar(title: Text("Search Item")),
      body: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
          RawKeyboardListener(
            focusNode: _textNode,
            key: UniqueKey(),
            onKey: handleKey,
            child: TextField(
              key: UniqueKey(),
              controller: _controller,
            ),
          ),
          SizedBox(
            height: 20.0,
          ),
          Text(_keyPressed),
        ],
      ),
    );
  }

  handleKey(RawKeyEvent key) {
    if (key.runtimeType.toString() == 'RawKeyUpEvent') {
      RawKeyEventDataAndroid data = key.data as RawKeyEventDataAndroid;
      String _keyCode;
      _keyCode = data.keyCode.toString();
      print(_keyCode);
      if (_keyCode == '19') {
        print('up pressed');
        _controller.selection =
            TextSelection.collapsed(offset: _controller.text.length - 3);
      }
    }
  }
}

颤振覆盖文本字段的上/下键行为

1 个答案: