Flutter文件下载插件file_downloader_flutter的使用

file_downloader_flutter 是一个允许你在Flutter应用中从URL下载文件（如图片、文档等）的插件。

预览

安装

1. 添加依赖到 pubspec.yaml

dependencies:
  file_downloader_flutter: <latest-version>

获取最新版本，请访问 pub.dev

2. 导入包

import 'package:file_downloader_flutter/file_downloader_flutter.dart';

3. 添加按钮点击事件

try {
  FileDownloaderFlutter().urlFileSaver(url: controller.text);
} catch(e) {
  print(e);
}

平台特定配置

Android

1. 将 android/app/build.gradle 文件中的最小Android SDK版本更改为21（或更高）。

   minSdkVersion 21
   

2. 在 AndroidManifest.xml 中添加 INTERNET 权限。

   <uses-permission android:name="android.permission.INTERNET" />
   

许可证

MIT License
Copyright (c) 2024 Divyang Parmar
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

示例代码

以下是一个完整的示例代码，展示了如何在Flutter应用中使用 file_downloader_flutter 插件来下载文件。

import 'package:file_downloader_flutter/file_downloader_flutter.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';

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

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'File saver',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: 'Url to file saver'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  TextEditingController controller = TextEditingController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: Center(
        child: Padding(
          padding: const EdgeInsets.all(8.0),
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              TextField(controller: controller),
              MaterialButton(
                onPressed: () {
                  try {
                    FileDownloaderFlutter().urlFileSaver(url: controller.text);
                  } catch (e) {
                    if (kDebugMode) {
                      print(e);
                    }
                  }
                },
                child: const Text("Save file"),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

在这个示例中，我们创建了一个简单的Flutter应用，包含一个输入框和一个按钮。用户可以在输入框中输入文件的URL，点击按钮后，应用会调用 FileDownloaderFlutter().urlFileSaver 方法下载文件。