如何更改 flutter 中驗證器文本的顏色？

Question

我在 flutter 應用程序中有密碼文本字段，它有一個與之關聯的驗證器，工作正常。 下面是相同的代碼

String pwdValidator(String value) {

  if (value.length < 6) {
    return 'Password must be longer than 6 characters';
  } else {
    return null;
  }
}

final passwordField = TextFormField(
  decoration: InputDecoration(
    labelText: 'Password',

    prefixIcon: Icon(
      LineIcons.lock,
      color: Colors.white,
    ),
    enabledBorder: UnderlineInputBorder(
      borderSide: BorderSide(color: Colors.white),
    ),
    focusedBorder: UnderlineInputBorder(
      borderSide: BorderSide(color: Colors.white),
    ),
  ),
  keyboardType: TextInputType.text,
  obscureText: true,
  validator: pwdValidator,
  controller: pwdInputController,
);

你可以在上面看到整個代碼。 我對這段工作代碼有疑問，那就是我無法更改密碼驗證器的文本顏色，我的意思是當用戶按下提交按鈕時，如果密碼字段的長度不夠大。 我應該如何改變相同的顏色？

Answer 1

您可以在下面復制粘貼運行完整代碼
您可以使用errorStyle並根據您的要求設置TextStyle
代碼片段

TextFormField(
            decoration: InputDecoration(
              labelText: 'Password',
              errorStyle: TextStyle(color: Colors.orange),

工作演示

完整代碼

import 'package:flutter/material.dart';

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

/// This Widget is the main application widget.
class MyApp extends StatelessWidget {
  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      home: Scaffold(
        appBar: AppBar(title: const Text(_title)),
        body: MyStatelessWidget(),
      ),
    );
  }
}

/// This is the stateless widget that the main application instantiates.
class MyStatelessWidget extends StatefulWidget {
  MyStatelessWidget({Key key}) : super(key: key);

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

class _MyStatelessWidgetState extends State<MyStatelessWidget> {
  final _formKey = GlobalKey<FormState>();

  String pwdValidator(String value) {
    if (value.length < 6) {
      return 'Password must be longer than 6 characters';
    } else {
      return null;
    }
  }

  @override
  Widget build(BuildContext context) {
    return Form(
      key: _formKey,
      child: Column(
        children: [
          TextFormField(
            decoration: InputDecoration(
              labelText: 'Password',
              errorStyle: TextStyle(color: Colors.orange),
              prefixIcon: Icon(
                Icons.description,
                color: Colors.white,
              ),
              enabledBorder: UnderlineInputBorder(
                borderSide: BorderSide(color: Colors.white),
              ),
              focusedBorder: UnderlineInputBorder(
                borderSide: BorderSide(color: Colors.white),
              ),
            ),
            keyboardType: TextInputType.text,
            obscureText: true,
            validator: pwdValidator,
            //controller: pwdInputController,
          ),
          RaisedButton(
            onPressed: () {
              // Validate returns true if the form is valid, otherwise false.
              if (_formKey.currentState.validate()) {}
            },
            child: Text('Submit'),
          )
        ],
      ),
    );
  }
}