Flutter DateTimeFormField提示文本颜色不变

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(
        // 修改DateTimeFormField的提示文本颜色
        inputDecorationTheme: InputDecorationTheme(
          hintStyle: TextStyle(color: Colors.red), // 设置提示文本颜色为红色
        ),
      ),
      home: Scaffold(
        appBar: AppBar(
          title: Text('DateTimeFormField示例'),
        ),
        body: Center(
          child: DateTimeFormField(
            decoration: InputDecoration(
              hintText: '选择日期和时间',
            ),
            onDateSelected: (DateTime value) {
              print(value);
            },
          ),
        ),
      ),
    );
  }
}