flutter的TextField如何提示验证错误

可以通过更新状态并传递一个新的InputDecoration对象来完成：

class MyAppHome extends StatefulWidget {
  @override
  _MyAppHomeState createState() => _MyAppHomeState();
}

class _MyAppHomeState extends State<MyAppHome> {
  String _errorText; @override
  Widget build(BuildContext context) { return new Scaffold( body: Center( child: TextField( onSubmitted: (String text) { setState(() { if (text != "Hello") { _errorText = 'Error: This is not an email'; } else { _errorText = null; } }); }, decoration: InputDecoration( hintText: "This is a hint", errorText: _getErrorText(), ), ), ), );
  } _getErrorText() { return _errorText;
  }
}

  

 

  
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文章来源: blog.csdn.net，作者：WongKyunban，版权归原作者所有，如需转载，请联系作者。

原文链接：blog.csdn.net/weixin_40763897/article/details/108210352