问题描述
如何在 TextFormField 中粘贴验证文本。默认情况下它低于
文本框
但它是这样显示的
我查看了各种来源,但没有找到合适的答案
有没有办法在文本框内显示验证文本
解决方法
如果某个文本字段的验证失败,您可以从 TextEditingController 更新文本,也可以从控制器的“onTap”属性中删除文本。
TextEditingController _passwordController = TextEditingController();
if(condition)
{
//success call
}
else
{
setState((){
_passwordController.text="Password Does not match
});
}
,
您应该通过以下方式验证您的表单
class MyForm extends StatefulWidget {
@override
MyFormState createState() {
return MyFormState();
}
}
// Create a corresponding State class.
// This class holds data related to the form.
class MyFormState extends State<MyForm> {
// Create a global key that uniquely identifies the Form widget
// and allows validation of the form.
//
// Note: This is a GlobalKey<FormState>,// not a GlobalKey<MyFormState>.
final _formKey = GlobalKey<FormState>();
@override
Widget build(BuildContext context) {
// Build a Form widget using the _formKey created above.
return Form(
key: _formKey,child: Column(
crossAxisAlignment: CrossAxisAlignment.start,children: <Widget>[
TextFormField(
// The validator receives the text that the user has entered.
validator: (value) {
if (value == null || value.isEmpty) {
return 'Please enter some text';
}
return null;
},),Padding(
padding: const EdgeInsets.symmetric(vertical: 16.0),child: ElevatedButton(
onPressed: () {
// Validate returns true if the form is valid,or false otherwise.
if (_formKey.currentState!.validate()) {
// If the form is valid,display a snackbar. In the real world,// you'd often call a server or save the information in a database.
// sendData();
ScaffoldMessenger.of(context)
.showSnackBar(SnackBar(content: Text('Processing Data')));
}
},child: Text('Submit'),],);
}
}
,
有点问题。我试过了,但文本字段的验证器属性不支持。