Flutter PDF处理插件flutter_pdf_plugin的使用

在Flutter应用中处理PDF文件可以通过使用flutter_pdf_plugin插件来实现。本文将详细介绍如何在Flutter项目中使用该插件，并提供完整的示例代码。

使用步骤

1. 添加依赖

首先，在项目的pubspec.yaml文件中添加flutter_pdf_plugin依赖：

dependencies:
  flutter_pdf_plugin: ^1.0.0

2. 加载依赖

在终端中运行以下命令以加载新的依赖项：

flutter packages get

3. 导入库

在Dart代码中导入flutter_pdf_plugin库：

import 'package:flutter_pdf_plugin/flutter_pdf_plugin.dart';

4. 加载网络地址PDF文件

通过网络地址加载PDF文件：

Navigator.of(context).push(new MaterialPageRoute(builder: (BuildContext context) { 
  return PdfNetScaffold(
      pdfUrl: "http://www.jinbangshichuang.com/20201209105650.pdf");
}));

5. 加载本地PDF文件

通过本地文件路径加载PDF文件：

class MyApp extends StatefulWidget {
  [@override](/user/override)
  _MyAppState createState() => new _MyAppState();
}

class _MyAppState extends State<MyApp> {
  String pathPDF = "";

  [@override](/user/override)
  void initState() {
    super.initState();
    createFileOfPdfUrl().then((f) {
      setState(() {
        pathPDF = f.path;
        print(pathPDF);
      });
    });
  }

  Future<File> createFileOfPdfUrl() async {
    final url = "http://africau.edu/images/default/sample.pdf";
    final filename = url.substring(url.lastIndexOf("/") + 1);
    var request = await HttpClient().getUrl(Uri.parse(url));
    var response = await request.close();
    var bytes = await consolidateHttpClientResponseBytes(response);
    String dir = (await getApplicationDocumentsDirectory()).path;
    File file = new File('$dir/$filename');
    await file.writeAsBytes(bytes);
    return file;
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Plugin example app')),
      body: Center(
        child: RaisedButton(
          child: Text("Open PDF"),
          onPressed: () => Navigator.push(
            context,
            MaterialPageRoute(builder: (context) => PDFScreen(pathPDF)),
          ),
        ),
      ),
    );
  }
}

class PDFScreen extends StatelessWidget {
  String pathPDF = "";
  PDFScreen(this.pathPDF);

  [@override](/user/override)
  Widget build(BuildContext context) {
    return PdfScaffold(
        appBar: AppBar(
          title: Text("Document"),
          actions: <Widget>[
            IconButton(
              icon: Icon(Icons.share),
              onPressed: () {},
            ),
          ],
        ),
        path: pathPDF);
  }
}

完整示例代码

以下是完整的示例代码，包括主入口点main.dart和其他相关类。

import 'dart:async';
import 'dart:io';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_pdf_plugin/pdf_viewer_scaffold.dart';
import 'package:path_provider/path_provider.dart';

void main() {
  runApp(MaterialApp(
    title: 'Plugin example app',
    home: MyApp(),
  ));
}

class MyApp extends StatefulWidget {
  [@override](/user/override)
  _MyAppState createState() => new _MyAppState();
}

class _MyAppState extends State<MyApp> {
  String pathPDF = "";

  [@override](/user/override)
  void initState() {
    super.initState();
    createFileOfPdfUrl().then((f) {
      setState(() {
        pathPDF = f.path;
        print(pathPDF);
      });
    });
  }

  Future<File> createFileOfPdfUrl() async {
    final url = "http://africau.edu/images/default/sample.pdf";
    final filename = url.substring(url.lastIndexOf("/") + 1);
    var request = await HttpClient().getUrl(Uri.parse(url));
    var response = await request.close();
    var bytes = await consolidateHttpClientResponseBytes(response);
    String dir = (await getApplicationDocumentsDirectory()).path;
    File file = new File('$dir/$filename');
    await file.writeAsBytes(bytes);
    return file;
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Plugin example app')),
      body: Center(
        child: RaisedButton(
          child: Text("Open PDF"),
          onPressed: () => Navigator.push(
            context,
            MaterialPageRoute(builder: (context) => PdfLocalPage(pathPDF)),
          ),
        ),
      ),
    );
  }
}

class PdfLocalPage extends StatelessWidget {
  String localPath = "";
  PdfLocalPage(this.localPath);

  [@override](/user/override)
  Widget build(BuildContext context) {
    return PdfScaffold(
      appBar: AppBar(title: Text("加载本地路径")),
      path: localPath,
    );
  }
}