Flutter文件下载插件fl_download的使用

开始使用

fl_download 是一个基于Dio实现的Flutter插件，用于文件下载。它简单、方便且快速，开箱即用，适用于Android、iOS等平台。

使用方法

示例代码

import 'dart:io';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:path_provider/path_provider.dart';
import 'package:fl_download/download/down_file.dart';
import 'package:fl_download/fl_download.dart';

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

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

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  String _platformVersion = 'Unknown';
  final _flDownloadPlugin = FlDownload();

  // 获取app临时文件路径
  Future<String> getFilePath(String type) async {
    var filepath = await getApplicationDocumentsDirectory(); // App内部file:data.com.nufang.zao/file/
    var file = Directory('${filepath.path}/$type');
    try {
      bool exists = await file.exists();
      if (!exists) {
        await file.create();
      }
    } catch (e) {
      if (kDebugMode) {
        print(e);
      }
    }
    return file.path;
  }

  @override
  void initState() {
    super.initState();
    initPlatformState();
    downloadDemo();
  }

  downloadDemo() async {
    String filePath = await getFilePath('download');
    String tempFilePath = '$filePath/${12345678}.mp3';
    
    // 下载音频文件
    DownFile().downInfo(
      'https://downsc.chinaz.net/files/download/sound1/201305/3055.mp3', // 文件URL
      tempFilePath, // 保存路径
      () async {
        if (kDebugMode) {
          print(("下载完成"));
        }
      },
    );

    // 下载视频文件到相册
    DownFile().downVideoToDCIM(
      "music_audio", // 目录名
      'https://music-aigc-bj-1256122840.cos.ap-beijing.myqcloud.com/bjprod/ai/youtube/5nmtCPO1NFY.m4a', // 文件URL
      () {
        if (kDebugMode) {
          print("下载成功");
        }
      },
    );
  }

  // Platform messages are asynchronous, so we initialize in an async method.
  Future<void> initPlatformState() async {
    String platformVersion;
    // Platform messages may fail, so we use a try/catch PlatformException.
    // We also handle the message potentially returning null.
    try {
      platformVersion = await _flDownloadPlugin.getPlatformVersion() ?? 'Unknown platform version';
    } on PlatformException {
      platformVersion = 'Failed to get platform version.';
    }

    // If the widget was removed from the tree while the asynchronous platform
    // message was in flight, we want to discard the reply rather than calling
    // setState to update our non-existent appearance.
    if (!mounted) return;

    setState(() {
      _platformVersion = platformVersion;
    });
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('插件示例应用'),
        ),
        body: Center(
          child: Text('运行在: $_platformVersion\n'),
        ),
      ),
    );
  }
}

说明

1. 获取文件路径：

   Future<String> getFilePath(String type) async {
     var filepath = await getApplicationDocumentsDirectory(); // 获取应用程序文档目录
     var file = Directory('${filepath.path}/$type'); // 创建指定类型的文件夹
     try {
       bool exists = await file.exists();
       if (!exists) {
         await file.create(); // 如果文件夹不存在，则创建
       }
     } catch (e) {
       if (kDebugMode) {
         print(e); // 打印错误信息
       }
     }
     return file.path; // 返回文件夹路径
   }
   

2. 下载文件：

   DownFile().downInfo(
     'https://downsc.chinaz.net/files/download/sound1/201305/3055.mp3', // 文件URL
     tempFilePath, // 保存路径
     () async {
       if (kDebugMode) {
         print(("下载完成")); // 打印下载完成信息
       }
     },
   );
   

3. 下载视频文件到相册：

   DownFile().downVideoToDCIM(
     "music_audio", // 目录名
     'https://music-aigc-bj-1256122840.cos.ap-beijing.myqcloud.com/bjprod/ai/youtube/5nmtCPO1NFY.m4a', // 文件URL
     () {
       if (kDebugMode) {
         print("下载成功"); // 打印下载成功信息
       }
     },
   );