无法下标[MPMediaItem]类型的值 [英] cannot subscript a value of type [MPMediaItem]

问题描述

我正在尝试执行此代码，以获取用户可以在手机上拥有的所有音乐播放列表.

I am trying to execute this code in order to get all the music playlists that the users can have on their phones.

    var queryPlaylists = MPMediaQuery.playlistsQuery()
    print(queryPlaylists.collections[0])

但是，当我尝试访问queryPlaylists.collections的任何元素时，都会出现编译错误:

However, when I try to access any of the elements of queryPlaylists.collections I get a compilation error:

无法下标[MPMediaItem]类型的值.

Cannot subscript a value of type [MPMediaItem].

自从上面的数组以来，这对我来说没有任何意义.此外，该功能以前在xcode 7.0之前有效.

This does not make any sense to me since the above in an array. In addition this used to work before xcode 7.0.

推荐答案

我想出了要访问queryPlaylists中的元素的方法，您需要创建一个新变量并将其转换为

I figured out in order to access the elements in the queryPlaylists you need to create a new variable and cast it to [MPMediaPlaylist] as

var播放列表= queryPlaylists.collections为！ [MPMediaPlaylist]

var playlists = queryPlaylists.collections as! [MPMediaPlaylist]

现在您可以访问播放列表的元素

now you can access the elements of playlists

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