如何显示流式 Apple Music 的专辑插图？

Question

在我的音乐播放器中使用新的 Apple Music API（2016 年 5 月 12 日发布）在 iOS 9（swift，虽然我目前正在熟悉 Objective-C），我可以显示流媒体歌曲的信息，但不能显示插图。我正在使用 MediaPlayer、UIKit 和 StoreKit 框架。我已成功请求对 AddToCloudMusicLibrary 和 MusicCatalogPlayback 的授权。我成功地显示了我从 Apple Music 应用程序下载的歌曲中的 Apple Music 插图，以及我个人歌曲 collection 中的插图。我见过其他人有这方面的问题，没有运气......

在我求助于显示默认图像（这对 error-handling 来说是必要的）之前，我只是想再问一次，为了人们，或者从替代服务中提取。任何帮助都会很棒！在我的代码中并不是真正的错误，所以我不会显示它，除非被要求帮助解决这个问题。

我第一次尝试发布代码...这是我在名为 Authorization 的 swift 文件中的内容。我需要在任何地方引用此代码还是应该在 AppDelegate 文件中？这是我项目中唯一我不是 100% 确定的部分。

import StoreKit
import MediaPlayer
import UIKit

class AppleMusicPlayer: NSObject {

    let applePlayer = MPMusicPlayerController.systemMusicPlayer()

    func playID(productID: String) {
        SKCloudServiceController.requestAuthorization { status in
            let controller = SKCloudServiceController()
            controller.requestCapabilitiesWithCompletionHandler { capabilities, error in
                if capabilities != SKCloudServiceCapability.None {
                    MPMediaLibrary.defaultMediaLibrary().addItemWithProductID(productID) { entities, error in
                        self.appPlayer.setQueueWithStoreIDs([productID])
                        self.appPlayer.shuffleMode = .Songs
                        self.appPlayer.play()
                    }
                }
            }
        }
    }
}

Answer 1

在 MediaItem class 中有一个名为 MPMediaItemPropertyArtwork 的属性。您将能够通过以下方式检索专辑的插图：

MPMediaItemArtwork *artwork = [mediaItem valueForProperty:MPMediaItemPropertyArtwork];
UIImage *albumImage = [itemArtwork imageWithSize:cgSizeYouWant];

Answer 2

这是 Apple Music 当前 API 中的一个错误。正如您提到的，不在用户库中但从 AM 流式传输的歌曲不会 return 专辑封面。

您应该在 bugreport.apple.com 提交功能增强（您也可以从 6 个月前 25413082 复制我的）。

与此同时，您最好的选择是使用 iTunes api 检索专辑插图，不幸的是，这并不是 return 100% 正确的结果...

Answer 3

我为此苦苦挣扎了一段时间。如果这是一个实际的错误，我不确定，但是您不能像您期望的那样将 UIImageView 设置为 nowPlayingItem。您必须从 Apple Music 服务中提取图像 api。请参阅文档 here. Also have a look at the sample project here that Apple provides for a full understanding. Also here 是我如何克服此问题的完整示例。

func updateUserInterface() {
    if musicPlayerManager.musicPlayerController.playbackState == .playing { //Check if anything is playing
        if let currentItem = musicPlayerManager.musicPlayerController.nowPlayingItem {
            songAlbumLabel.text = currentItem.albumTitle
            songTitleLabel.text = currentItem.title
            songArtistNameLabel.text = currentItem.artist
            let albumTitle = currentItem.albumTitle  //Changes here!
            let artist = currentItem.artist  //Changes here!
            if let artwork = musicPlayerManager.musicPlayerController.nowPlayingItem?.artwork, let image = artwork.image(at: artworkImageView.frame.size) { // Check for local image
                print("using local image")
                artworkImageView.image = image 
        } else { 
            guard let developerToken = appleMusicManager.fetchDeveloperToken() else {print("oops");return}
            let searchTypes = "songs"
            var searchURLComponents = URLComponents()
            searchURLComponents.scheme = "https"
            searchURLComponents.host = "api.music.apple.com"
            searchURLComponents.path = "/v1/catalog/"
            searchURLComponents.path += "\(authorizationManager.cloudServiceStoreFrontCountryCode)"
            searchURLComponents.path += "/search"
            let expectedArtist = artist?.replacingOccurrences(of: " ", with: "+")  //Changes here!
            let artistExpected = expectedArtist?.replacingOccurrences(of: "&", with: "")  //Changes here!
            let expectingArtist = artistExpected?.replacingOccurrences(of: "++", with: "+")  //Changes here!
            let expectedAlbum = albumTitle?.replacingOccurrences(of: " ", with: "+")  //Changes here!
            searchURLComponents.queryItems = [
                    URLQueryItem(name: "term", value: (expectingArtist! + "-" + expectedAlbum!)),
                    URLQueryItem(name: "types", value: searchTypes)
                ]  //Changes here!
            var request = URLRequest(url: searchURLComponents.url!)
            request.httpMethod = "GET"
            request.addValue("Bearer \(developerToken)", forHTTPHeaderField: "Authorization")
            let dataTask = URLSession.shared.dataTask(with: request) {
                (data, response, error) in
                print(response!)
                if let searchData = data {
                    guard let results = try? self.appleMusicManager.processMediaItemSections(searchData) else { return}
                    self.mediaItem = results
                    let album = self.mediaItem[0][0]
                    let albumArtworkURL = album.artwork.imageUrl(self.artworkImageView.frame.size)
                    if let image = self.imageManager.cachedImage(url: albumArtworkURL) {
                        print("using cached image")
                        self.artworkImageView.image = image
                    }
                    else {
                        self.imageManager.fetchImage(url: albumArtworkURL) {(image) in
                            print("fetching image")
                            self.artworkImageView.image = image
                        }
                    }
                }
            }
            dataTask.resume()
        }
    } else { // Need to set it to some kind of default values
        artworkImageView.image = nil
        songArtistNameLabel.text = " "
        songTitleLabel.text = " "
        songAlbumLabel.text = " "
        }
    }
}

Answer 4

我发现的最佳方法是使用从目录 Apple Music API 请求中获取歌曲，documented here。

您只需要传入歌曲标识符（用于播放的那个）和用于播放歌曲的店面标识符。与使用可能会失败的搜索请求的答案相比，这总是会产生准确的结果。

如何显示流式 Apple Music 的专辑插图？

How to display album artwork of streamed Apple Music?

ios

objective-c

swift

media-player

apple-music