Flutter PDF页面提取插件extract_pdf_page的使用

Flutter PDF页面提取插件extract_pdf_page的使用

获取开始

这个项目是一个新的Flutter插件项目，用于在Android和/或iOS上实现平台特定的代码。

使用说明

本示例展示了如何使用extract_pdf_page插件来下载PDF文件并提取其中的页面。以下是完整的示例代码：

import 'dart:io';

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

import 'package:flutter/services.dart';
import 'package:extract_pdf_page/extract_pdf_page.dart';
import 'package:http/http.dart' as http;
import 'package:path_provider/path_provider.dart';

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

class MyApp extends StatefulWidget {
  const MyApp({super.key});

  [@override](/user/override)
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  List<String> result = List.empty(growable: true);
  final _extractPdfPagePlugin = ExtractPdfPage();

  [@override](/user/override)
  void initState() {
    super.initState();
    downloadAndSaveFile();
    initPlatformState();
  }

  Future<void> downloadAndSaveFile() async {
    // 文件下载地址
    const String fileUrl =
        'https://han01.vstorage.vngcloud.vn/v1/AUTH_f42e8dc502e04ee5b4ff28982239069a/test-1-container/s3_5d4e1e1a-35ac-4e4d-9d36-61e5d3945688.pdf';

    // 获取临时目录
    final Directory tempDir = await getTemporaryDirectory();
    final String filePath = '${tempDir.path}/conversation-game.pdf';

    try {
      // 下载文件
      final http.Response response = await http.get(Uri.parse(fileUrl));

      if (response.statusCode == 200) {
        // 将文件保存到临时目录
        final File file = File(filePath);
        await file.writeAsBytes(response.bodyBytes);
        print('文件已保存至: $filePath');
        try {
          // 提取PDF文件的第一页
          final listResult =
              await _extractPdfPagePlugin.extractPagesPDF(filePath, "123");
          print('成功提取的页数: ${listResult.length}');
        } on PlatformException {
          print('提取页数失败:');
          result = List.empty();
        }
      } else {
        print('文件下载失败: ${response.statusCode}');
      }
    } catch (e) {
      print('错误: $e');
    }
  }

  Future<void> initPlatformState() async {
    List<String> listResult;
    try {
      // 初始化插件状态
      listResult =
          await _extractPdfPagePlugin.extractPagesPDF("inputUrl", "123");
    } on PlatformException {
      result = List.empty();
    }

    if (!mounted) return;

    setState(() {
      // result.addAll(listResult);
    });
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('插件示例应用'),
        ),
        body: Center(
          child: Text('运行结果: ${result.length}\n'),
        ),
      ),
    );
  }
}

代码解释

1. 导入必要的库

   import 'dart:io';
   import 'package:flutter/material.dart';
   import 'dart:async';
   import 'package:flutter/services.dart';
   import 'package:extract_pdf_page/extract_pdf_page.dart';
   import 'package:http/http.dart' as http;
   import 'package:path_provider/path_provider.dart';
   

2. 定义主应用类

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

3. 初始化状态

   class MyApp extends StatefulWidget {
     const MyApp({super.key});
   
     [@override](/user/override)
     State<MyApp> createState() => _MyAppState();
   }
   
   class _MyAppState extends State<MyApp> {
     List<String> result = List.empty(growable: true);
     final _extractPdfPagePlugin = ExtractPdfPage();
   
     [@override](/user/override)
     void initState() {
       super.initState();
       downloadAndSaveFile();
       initPlatformState();
     }
   

4. 下载并保存文件

   Future<void> downloadAndSaveFile() async {
     const String fileUrl = 'https://han01.vstorage.vngcloud.vn/v1/AUTH_f42e8dc502e04ee5b4ff28982239069a/test-1-container/s3_5d4e1e1a-35ac-4e4d-9d36-61e5d3945688.pdf';
   
     final Directory tempDir = await getTemporaryDirectory();
     final String filePath = '${tempDir.path}/conversation-game.pdf';
   
     try {
       final http.Response response = await http.get(Uri.parse(fileUrl));
       if (response.statusCode == 200) {
         final File file = File(filePath);
         await file.writeAsBytes(response.bodyBytes);
         print('文件已保存至: $filePath');
         try {
           final listResult = await _extractPdfPagePlugin.extractPagesPDF(filePath, "123");
           print('成功提取的页数: ${listResult.length}');
         } on PlatformException {
           print('提取页数失败:');
           result = List.empty();
         }
       } else {
         print('文件下载失败: ${response.statusCode}');
       }
     } catch (e) {
       print('错误: $e');
     }
   }
   

5. 初始化插件状态

   Future<void> initPlatformState() async {
     List<String> listResult;
     try {
       listResult = await _extractPdfPagePlugin.extractPagesPDF("inputUrl", "123");
     } on PlatformException {
       result = List.empty();
     }
   
     if (!mounted) return;
   
     setState(() {
       // result.addAll(listResult);
     });
   }
   

6. 构建UI

   [@override](/user/override)
   Widget build(BuildContext context) {
     return MaterialApp(
       home: Scaffold(
         appBar: AppBar(
           title: const Text('插件示例应用'),
         ),
         body: Center(
           child: Text('运行结果: ${result.length}\n'),
         ),
       ),
     );
   }