将播放列表轨道分配给3D阵列

Question

所以我在使用Spotify的API进行实验时遇到了我遇到过的最复杂的问题。 我有流派文本文件，例如“ Chill”或“ House”。 在这些文件中，我具有指向Spotify播放列表的链接。 这些行的第一行代表我的这一类型的播放列表，例如：

myplalyist-ID 
random1-ID 
random2-ID ...

现在，由于这些链接指向播放列表，因此这些播放列表包含曲目。 现在，我想从那些随机播放列表中获取所有曲目，并将其放入我的曲目中（在这里过滤和添加曲目不是问题，只是为了您有所了解）。 现在我想我可以创建一个3D阵列来处理这些轨道，例如：

1D: genre1    - genre2    - genre3
2D: playlist1 - playlist2 - playlist3
3D: tracks1   - tracks2   - tracks3

希望您能理解我的意思，我希望能够通过以下方式访问播放列表轨道：

foreach(PlaylistTrack track in array[genre][playlist])
    // filter & add "track"

因此，我的处理方法如下：

//PlaylistTrack is the type in which Spotify stores a track within a Playlist
private List<PlaylistTrack>[,,] playlistTracks;//3D???
//this is to store the amount of playlists within a genre
private int[] playlistArray;
//int to save the amount of genre-files
private int fileCount;

//-----------------METHOD:

private void getTracks()
{
    DirectoryInfo dir = new DirectoryInfo(this.path);//directory where genres are stored

    this.fileCount = 0;

    foreach (var file in dir.GetFiles("*.txt"))
    {
        if (file.Name != "My Tracks.txt" && file.Name != "Tracks.txt")//getting all genre textfiles
        {
            this.fileCount++;
        }
    }

    this.playlistArray = new int[this.fileCount];

    //i know using the foreach over and over is kinda bad and not preofessional,
    //but i don't use c# on a daily base and i didn't knew how to get it done otherwise

    int count = 0;
    foreach (var file in dir.GetFiles("*.txt"))
    {
        if (file.Name != "My Tracks.txt" && file.Name != "Tracks.txt")
        {
            int count2 = 0;
            if (File.ReadAllText(file.FullName) != "")
            {
                using (StreamReader sr = new StreamReader(file.FullName))
                {
                    string line = "";
                    while ((line = sr.ReadLine()) != null)
                    {
                        if (line != "")
                        {
                            count2++;
                        }
                    }
                }

            }
            this.playlistArray[count] = count2;
            count++;
        }
    }

    for (int i = 0; i < this.fileCount; i++)
        this.playlistTracks[i] = new List<PlaylistTrack>[this.playlistArray[i]]();
    //here i'm stuck, how would i initialize the array, so it can holds a bunch of PlaylistTrack Items in "3rd row", 
    //accessable through [genre][playlist]
}

非常感谢您的帮助，因为我对此一无所知！ :)

编辑：那就是我尝试的：

//Setting File-Count to 0
this.fileCount = 0;

//Init new Dictionary
var allTracks = new Dictionary<string, Dictionary<string, List<PlaylistTrack>>>();

//Getting Directory where Genre-Files are
DirectoryInfo dir = new DirectoryInfo(this.path);

int count = 0;
//Looping through files in this Directory #1
foreach (var file in dir.GetFiles("*.txt"))
{
    //Get only Genre-Files, not Track-Lists
    if (file.Name != "My Tracks.txt" && file.Name != "Tracks.txt")
    {
        count++;
    }
}

//Init new string Array that will hold the Links to my Playlist for every genre
this.playlistLinks = new string[count];

//Looping through files in this Directory #2
foreach (var file in dir.GetFiles("*.txt"))
{
    //Get only Genre-Files, not Track-Lists
    if(file.Name != "My Tracks.txt" && file.Name != "Tracks.txt")
    {
        //If the Genre-File has content
        if (File.ReadAllText(file.FullName) != "")
        {
            //Getting the Genre Name, by splitting the Genre-File-Name
            string name = file.Name.Split(new string[] { ".txt" }, StringSplitOptions.None)[0];

            //Reading the Genre-File
            using (StreamReader sr = new StreamReader(file.FullName))
            {
                string line = "";
                bool first = false;
                //If the new line has content
                while ((line = sr.ReadLine()) != null)
                {
                    //If it's not the first line and the line is not ""
                    if (first && line != "")
                    {
                        //Splitting line to get Data
                        //split[0] = PlaylistID; split[1] = OwnerID
                        string[] split = line.Split(new string[] { " // " }, StringSplitOptions.None);
                        //Getting Playlist Tracks and storing them in the Dictionary
                        //HERE HAPPENS THE ERROR
                        allTracks[name][split[0]] = this.getPlaylistTracks(split[1], split[0]);

                        //Looping through the Playlist-Tracks within the Dictionary
                        foreach (PlaylistTrack tr in allTracks [name][split[0]])
                        {
                            //If the Track is on Spotify's Servers
                            if (!tr.IsLocal)
                            {
                                //Filtering (not important here -> does work)
                                if (tr.AddedAt > time)
                                {
                                    //Creating a string that holds Track's info
                                    string write = tr.Track.Name + " // " + string.Join(",", tr.Track.Artists.Select(source => source.Name));
                                    //Filtering tracks that i haven't listened to, by checking if track exists in "My Tracks.txt"
                                    //(not important here -> does work)
                                    if (!this.foundTrack(write))
                                    {
                                        //Adding collected Tracks to another List, sorted by Genre
                                        //So all filtered Tracks from all Playlists within a genre are stored in one list
                                        this.tracksToAdd[this.fileCount].Add(tr);
                                    }
                                }
                            }
                        }
                    }
                    //If it's the first line where the line is not ""
                    if(!first && line != "")
                    {
                        string[] split = line.Split(new string[] { " // " }, StringSplitOptions.None);
                        //Getting the PlaylistID of my Playlist
                        this.playlistLinks[this.fileCount] = split[0];
                        first = true;
                    }
                }
            }
        }
        //Increasing on every new Genre-File
        this.fileCount++;
    }
}

错误发生，我在代码中标记了它。 错误消息是：

mscorlib.dll中发生了“ System.Collections.Generic.KeyNotFoundException”异常。 附加信息：在字典中未指定指定的键。

（大约从德语翻译）

Answer 1

由于每个播放列表可以具有不同数量的歌曲，因此您不需要固定大小的3D矩阵（ [,,,] ），而是数组的数组（ [][][] ）。 您可以在此问题中阅读它们之间的区别。

话虽如此，您可以使用PlayListTrack[][][]实现您想要的。 您可能会喜欢var allTracks = new PlayListTrack[amountOfGenres][][]; 然后将allTracks每一行初始化为PlayListTrack[][]其大小是与该行匹配的流派的播放列表的数量。 最后，您可以将每个播放列表初始化为PlayListTrack[]其大小是该给定播放列表的歌曲数量。

无论如何，我建议您看一下Dictionary <TKey，TValue>类，该类允许您将唯一键（例如，流派的Id）映射到值（例如，播放列表，可以是字典）本身）。

然后，您可能会遇到以下情况：

// Lists of tracks, indexed by their genre id (first string) and
// their playlist id (second string)
var allTracks = new Dictionary<string, Dictionary<string, List<PlayListTrack>>>();

// Examples

// Getting a genre, which is a Dictionary<string, List<PlayListTrack>>
var allJazzPlayLists = allTracks["jazz"];

// Getting a list of songs, which is a List<PlayListTrack>
var songs = allTracks["hip-hop"]["west side"];