Question

我正在尝试在我的应用中解决表单验证。每次单击TextFromField时，焦点都会丢失，键盘会隐藏。我发现问题在于“_formKey”。但我需要它来验证。怎么解决？

代码段

  class _TodoCreateDetailPageState extends State<TodoPage> {
  @override
  Widget build(BuildContext context) {
    final GlobalKey<FormState> _formKey = new GlobalKey<FormState>();

    String _title = widget.todo == null ? "New TODO" : widget.todo.title;
    String _message;

    return new Scaffold(
      appBar: new AppBar(
        title: new Text(_title),
      ),
      floatingActionButton: new FloatingActionButton(
          child: new Icon(Icons.save), onPressed: null),
      body: new Padding(
          padding: new EdgeInsets.all(20.0),
          child: new Form(
              key: _formKey,
              child: new Column(
                children: <Widget>[
                  new TextField(
                    decoration: new InputDecoration(labelText: 'Title'),
                    onChanged: (String value) {
                      _title = value;
                    },
                  ),
                  new TextField(
                    decoration: new InputDecoration(labelText: 'Message'),
                    onChanged: (String value) {
                      _message = value;
                    },
                  )
                ],
              ))),
    );
  }

Answer 1

正如Derek Lakin在评论中所说，将StatelessWidget更改为StatefulWidget对我有用。

Answer 2

您似乎知道问题出在密钥本身，例如#6783。解决方案是避免每次构造验证密钥。因此，您可以这样进行操作（甚至使其成为小部件的属性）：

class _TodoCreateDetailPageState extends State<TodoPage> {
  final GlobalKey<FormState> _formKey = new GlobalKey<FormState>();

  @override
  Widget build(BuildContext context) {
    String _title = widget.todo == null ? "New TODO" : widget.todo.title;
    String _message;

    return new Scaffold(
      appBar: new AppBar(
        title: new Text(_title),
      ),
      floatingActionButton: new FloatingActionButton(
          child: new Icon(Icons.save), onPressed: null),
      body: new Padding(
          padding: new EdgeInsets.all(20.0),
          child: new Form(
              key: _formKey,
              child: new Column(
                children: <Widget>[
                  new TextField(
                    decoration: new InputDecoration(labelText: 'Title'),
                    onChanged: (String value) {
                      _title = value;
                    },
                  ),
                  new TextField(
                    decoration: new InputDecoration(labelText: 'Message'),
                    onChanged: (String value) {
                      _message = value;
                    },
                  )
                ],
              ))),
    );
  }

Answer 3

我遇到了同样的问题，并且找到了解决方案，只需在build方法之外定义一个控制器变量即可。使用TextEditingController（）

Answer 4

尝试将焦点节点提供给文本字段。

new TextField(focusNode: new FocusNode(),

Answer 5

此问题是由于在build（）中使用了GlobalKey初始化

    final GlobalKey<FormState> _formKey = new GlobalKey<FormState>();
    //this will work fine when you move key outside the build();
    @override
    Widget build(BuildContext context){

    }

从构建中删除它，一切都很好。

  {
    "key": "ctrl+k ctrl+k",
    "when": "editorTextFocus",
    "command": "selectby.lineNr",
    "args": { "lineNrEx": "c-n==10" }
  },
  {
    "key": "ctrl+k ctrl+j",
    "when": "editorTextFocus",
    "command": "selectby.lineNr",
    "args": { "lineNrEx": "n-c==10" }
  }

TextFormField正在失去焦点 - 扑腾

5 个答案: