XMusicDownloader，一款 支持从百度、网易、qq和酷狗等音乐网站搜索并下载歌曲的程序。

缘起：

一直用网易音乐听歌，但是诸如李健、周杰伦的不少歌曲，网易都没有版权，要从QQ等音乐去下载，因此一直想写一个小程序，可以从其他音乐网站下载相关歌曲，趁放假，花了几小时做了这样一个程序。

BTW: 之前写过一个从酷狗和网易音乐提取缓存文件的程序，感兴趣的可以查看。

功能

• 聚合搜索多家音乐网站
• 支持音乐批量下载
• 搜索结果综合排序
• 可以编写Provider程序，支持其他音乐网站

实现IMusicProvider即可，主要是搜索和获取下载链接的方法。

    public interface IMusicProvider{string Name { get; }string getDownloadUrl(Song song);List<Song> SearchSongs(string keyword, int page, int pageSize);}

界面截图

下载程序

https://github.com/jadepeng/XMusicDownloader/releases

实现方案介绍

定义song实体

public class Song{public string id { get; set; }public string name { get; set; }public string singer { get; set; }public string album { get; set; }public string source { get; set; }public double duration { get; set; }public double size { get; set; }public string url { get; set; }public int rate { get; set; }public int index { get; set; }public string getFileName(){return singer + "-" + name + ".mp3";}public string getMergedKey(){return singer.Replace(" ", "") + name.Replace(" ", "");}}

封装各个音乐网站

抽象为MusicProvider，音乐提供方:)，定义Name为名称，SearchSongs搜索歌曲，getDownloadUrl获取音乐下载地址。

public interface IMusicProvider{string Name { get; }string getDownloadUrl(Song song);List<Song> SearchSongs(string keyword, int page, int pageSize);}

然后就是依次实现百度、网易等音乐网站，以QQ为例。

 public class QQProvider : IMusicProvider{static HttpConfig DEFAULT_CONFIG = new HttpConfig{Referer = "http://m.y.qq.com",};public string Name { get; } = "QQ";static string[] prefixes = new string[] { "M800", "M500", "C400" };public List<Song> SearchSongs(string keyword,int page,int pageSize){var searchResult = HttpHelper.GET(string.Format("http://c.y.qq.com/soso/fcgi-bin/search_for_qq_cp?w={0}&format=json&p={1}&n={2}", keyword, page,pageSize), DEFAULT_CONFIG);var searchResultJson = JsonParser.Deserialize(searchResult).data.song;var result = new List<Song>();var index = 1;foreach(var songItem in searchResultJson.list){var song = new Song{id = songItem["songmid"],name = songItem["songname"],album = songItem["albumname"],rate = 128,size = songItem["size128"],source = Name,index = index++,duration = songItem["interval"]};song.singer = "";foreach (var ar in songItem["singer"]){song.singer += ar["name"] + " ";}result.Add(song);}return result;}public string getDownloadUrl(Song song){var guid = new Random().Next(1000000000, 2000000000);var key = JsonParser.Deserialize(HttpHelper.GET(string.Format("http://base.music.qq.com/fcgi-bin/fcg_musicexpress.fcg?guid={0}&format=json&json=3",guid), DEFAULT_CONFIG)).key;foreach(var prefix in prefixes){var musicUrl = string.Format("http://dl.stream.qqmusic.qq.com/{0}{1}.mp3?vkey={2}&guid={3}&fromtag=1", prefix, song.id, key, guid);if (HttpHelper.GetUrlContentLength(musicUrl) > 0){return musicUrl;}}return null;}}

• 搜索调用http://c.y.qq.com/soso/fcgi-bin/search_for_qq_cp?w={0}&format=json&p={1}&n={2}接口，获取下载地址调用http://base.music.qq.com/fcgi-bin/fcg_musicexpress.fcg?guid={0}&format=json&json=3,然后再组合。

聚合搜索

设计一个MusicProviders，加载所有的IMusicProvider，提供一个SearchSongs方法，并发调用各个网站的搜索，然后merge到一起。

public List<MergedSong> SearchSongs(string keyword, int page, int pageSize){var songs = new List<Song>();Providers.AsParallel().ForAll(provider =>{var currentSongs = provider.SearchSongs(keyword, page, pageSize);songs.AddRange(currentSongs);});// mergereturn songs.GroupBy(s => s.getMergedKey()).Select(g => new MergedSong(g.ToList())).OrderByDescending(s => s.score).ToList();}

关于merge，核心就是将相同的歌曲合并到一起，我们暂且认为歌手+歌曲名相同的为同一首歌曲：

   public string getMergedKey(){return singer.Replace(" ", "") + name.Replace(" ", "");}

因此按megekey分组，就能实现聚合。我们设计一个MergedSong来包裹。

public class MergedSong{public List<Song> items{get; set;}public MergedSong(List<Song> items){this.items = items;}public string name{get{return this.items[0].name;}}public string singer{get{return this.items[0].singer;}}public string album{get{return this.items[0].album;}}public string source{get{return string.Join(",", this.items.Select(i => i.source).ToArray());}}public double duration{get{return this.items[0].duration;}}public double size{get{return this.items[0].size;}}public double rate{get{return this.items[0].rate;}}public double score{get{// 投票+排序加权  (各50%）return this.items.Count / (MusicProviders.Instance.Providers.Count - 1) + (20 - this.items.Average(i => i.index)) / 20;}}}

MergedSong的核心是定义了一个score，我们通过投票+搜索结果排序，用来决定合并结果的排序。

下载

下载主要是通过provider获取真实url，然后下载即可。

public class SongItemDownloader{MusicProviders musicProviders;string target;MergedSong song;public event DownloadFinishEvent DownloadFinish;public SongItemDownloader(MusicProviders musicProviders, string target, MergedSong song){this.musicProviders = musicProviders;this.target = target;this.song = song;}public long totalBytes;public long bytesReceived;public double ReceiveProgress;public double receiveSpeed;DateTime lastTime = DateTime.Now;public void Download(){WebClient client = new WebClient();client.DownloadProgressChanged += Client_DownloadProgressChanged;new Thread(() =>{// 多来源，防止单个来源出错foreach (var item in song.items){try{client.DownloadFile(musicProviders.getDownloadUrl(item), target + "\\" + item.getFileName());DownloadFinish?.Invoke(this, this);break;}catch{}}}).Start();}private void Client_DownloadProgressChanged(object sender, DownloadEventArgs e){this.bytesReceived = e.bytesReceived;this.totalBytes = e.totalBytes;this.receiveSpeed = e.receiveSpeed;this.ReceiveProgress = e.ReceiveProgress;}}

参考

• 程序界面，使用了https://github.com/Gsangu/KugouDownloader代码
• 搜索和下载方案参考 https://github.com/0xHJK/music-dl

作者：Jadepeng
出处：jqpeng的技术记事本--http://www.cnblogs.com/xiaoqi
您的支持是对博主最大的鼓励，感谢您的认真阅读。
本文版权归作者所有，欢迎转载，但未经作者同意必须保留此段声明，且在文章页面明显位置给出原文连接，否则保留追究法律责任的权利。