如何在flutter中用图片创建多页pdf？

dependencies:
  pdf: ^2.0.0

import 'package:pdf/pdf.dart';
import 'package:pdf/widgets.dart' as pw;

final pdf = pw.Document();

final imageProvider = pw.MemoryImage(imageBytes); // 使用图片字节创建ImageProvider
final image = pw.Image(imageProvider); // 创建Image对象
pdf.addPage(pw.Page(build: (pw.Context context) {
  return pw.Center(child: image); // 将图片居中显示在页面上
}));

final output = await getTemporaryDirectory(); // 获取临时目录
final file = File('${output.path}/example.pdf'); // 创建PDF文件
await file.writeAsBytes(await pdf.save()); // 将PDF文档保存到文件

import 'dart:io';
import 'package:flutter/material.dart';
import 'package:path_provider/path_provider.dart';
import 'package:pdf/pdf.dart';
import 'package:pdf/widgets.dart' as pw;

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter PDF Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Flutter PDF Demo'),
      ),
      body: Center(
        child: ElevatedButton(
          child: Text('Create PDF'),
          onPressed: () {
            createPDF();
          },
        ),
      ),
    );
  }

  Future<void> createPDF() async {
    final pdf = pw.Document();

    final imageProvider = pw.MemoryImage(imageBytes);
    final image = pw.Image(imageProvider);
    pdf.addPage(pw.Page(build: (pw.Context context) {
      return pw.Center(child: image);
    }));

    final output = await getTemporaryDirectory();
    final file = File('${output.path}/example.pdf');
    await file.writeAsBytes(await pdf.save());

    print('PDF created at: ${file.path}');
  }
}