Flutter桌面应用TextFormField粘贴文本时崩溃问题求助

我开发的Flutter桌面应用，往TextFormField粘贴文本时有50%概率崩溃，调试控制台仅显示错误信息：Lost connection to device. Exited (sigterm)，找不到相关问题排查方向，求帮助。

组件代码 #

Widget build(BuildContext context) {
    return Padding(
      padding: widget.padded
          ? const EdgeInsets.fromLTRB(13.0, 6.0, 13.0, 0.0)
          : const EdgeInsets.fromLTRB(2.0, 6.0, 2.0, 0.0),
      child: Row(
        children: [
          Expanded(
              child: TextFormField(
            onChanged: widget.onTextChanged,
            decoration: InputDecoration(
              hintText: widget.hintText,
              isDense: true,
              contentPadding:
                  const EdgeInsets.symmetric(horizontal: 13, vertical: 9),
            ),
            style: const TextStyle(fontSize: 11),
            maxLines: null,
            initialValue: widget.defaultText,
            expands: widget.expands,
          ))
        ],
      ),
    );
  }

必崩溃的示例文本 #

* Name
Sarah

* Date
2022/10/05

* Topic
Animals + Pets<Speaking>

* New Language
wildlife <noun>||animals, birds, and plants living in their natural environment
fox <noun>||a wild animal like a dog with red-brown fur, a pointed nose, and a long, thick tail
red panda <noun>||an animal with reddish-brown fur and a long bushy tail that lives mainly in trees, especially in China and Nepal
owl <noun>||a bird with a flat face and large eyes that hunts small mammals at night
swan <noun>||a large, usually white bird with a long neck that lives on rivers and lakes
breed <noun>||to keep animals for the purpose of producing young animals in a controlled way

* Pronunciation
bear||be~r

* Corrections
Four day, we start running||On the fourth day, we started running
in this trip||on this trip
I meet a lot of new friends||I have met a lot of new friends
There are many house made by wood ||... made of wood//i\The difference between 'made from', 'made of', and 'made by' can be tricky, so let me know if you need any help with them!\
I saw them in long distance||I saw them from far away//I saw them from a distance
They are originally from Russian||... from Russia

===

onChanged回调代码 #

onChanged: ((value) {
  if (_textController.text.endsWith('\n')) {
    // Add the prefix everytime a new line is created
    _textController.text += _linePrefix;
  }

  _text = value;
}),

问题根源及解决方案 #

核心问题 #

在onChanged里直接修改_textController.text会触发无限循环：

1. 粘贴文本触发onChanged
2. 修改控制器文本会再次触发onChanged
3. 反复触发导致应用资源耗尽，最终因sigterm崩溃

同时，TextFormField同时设置initialValue和外部控制器属于冲突配置，会加剧问题。

修复步骤 #

1. 统一用控制器管理文本，移除initialValue
   初始化时将默认值直接赋值给控制器，不再给TextFormField传递initialValue参数。

2. 改用控制器监听替代onChanged，避免循环触发
   监听控制器文本变化，修改文本时先临时移除监听，完成后重新添加，防止无限循环：

@override
void initState() {
  super.initState();
  // 初始化控制器默认值
  _textController.text = widget.defaultText;
  _textController.addListener(_handleTextChange);
}

@override
void dispose() {
  _textController.removeListener(_handleTextChange);
  _textController.dispose();
  super.dispose();
}

void _handleTextChange() {
  final currentText = _textController.text;
  // 避免重复添加前缀，先做判断
  if (currentText.endsWith('\n') && !currentText.endsWith('$_linePrefix\n')) {
    _textController.removeListener(_handleTextChange);
    _textController.text = currentText + _linePrefix;
    // 将光标定位到文本末尾
    _textController.selection = TextSelection.fromPosition(
      TextPosition(offset: _textController.text.length),
    );
    _textController.addListener(_handleTextChange);
  }
  _text = currentText;
}

// 修改TextFormField配置
TextFormField(
  controller: _textController,
  // 保留其他原有属性
)

3. 测试验证
   使用提供的示例文本进行粘贴测试，崩溃问题应该可以解决。

内容的提问来源于stack exchange，提问作者Michael Cullen