flutter :如何在flutter_pdfview中切换夜间模式

import 'package:flutter/material.dart';
import 'package:flutter_pdfview/flutter_pdfview.dart';

class PdfViewPage extends StatefulWidget {
  @override
  _PdfViewPageState createState() => _PdfViewPageState();
}

class _PdfViewPageState extends State<PdfViewPage> {
  bool isDarkMode = false;

  void toggleDarkMode() {
    setState(() {
      isDarkMode = !isDarkMode;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('PDF Viewer'),
      ),
      body: Container(
        child: Column(
          children: [
            RaisedButton(
              child: Text(isDarkMode ? '切换白天模式' : '切换夜间模式'),
              onPressed: toggleDarkMode,
            ),
            Expanded(
              child: PDFView(
                filePath: 'path_to_your_pdf_file',
                nightMode: isDarkMode,
              ),
            ),
          ],
        ),
      ),
    );
  }
}