显示.MP3文件的图稿 [英] Displaying Artwork for .MP3 file

问题描述

我正在尝试当前在ImageView中显示本地存储的.MP3曲目的专辑插图.有谁知道如何在Swift中获取此作品以完成此任务?

I am trying to currently display the album artwork for a locally stored .MP3 track in an ImageView. Does anyone know how to fetch this artwork in Swift in order to accomplish this?

我找到了此解决方案( iOS AVFoundation:如何从mp3文件中获取图片?)，但是代码是用Objective C编写的.我只想获取嵌入在MP3中的图像，然后将其显示在ImageView中.

I have found this solution (iOS AVFoundation: How do I fetch artwork from an mp3 file?) but the code is written in Objective C. I simply want to grab the image embedded in my MP3 and display it in my ImageView.

我查看了MPMediaItemArtwork的API文档，并在此找到了一个示例，该示例也可以实现我在Objective C中要完成的任务(

I've looked at the API documentation for the MPMediaItemArtwork and found an example that also accomplishes what I am trying to accomplish in Objective C as well here(http://www.codeitive.com/0zHjkUjUWX/not-able-to-get-the-uiimage-from-mpmediaitempropertyartwork.html) but cannot come up with a solution. My code is as follows:

import UIKit
import AVFoundation
import MediaPlayer

class ViewController: UIViewController {
let audioPath:NSURL! = NSBundle.mainBundle().URLForResource("SippinOnFire", withExtension: "mp3")

@IBOutlet var artistImage: UIImageView!
@IBOutlet var trackLabel: UILabel!
@IBOutlet var artistLabel: UILabel!
@IBOutlet var sliderValue: UISlider!
var player:AVAudioPlayer = AVAudioPlayer()


@IBAction func play(sender: AnyObject) {


    let audioInfo = MPNowPlayingInfoCenter.defaultCenter()
println(audioInfo)


    player.play()
    //println("Playing \(audioPath)")


    let playerItem = AVPlayerItem(URL: audioPath)
    let metadataList = playerItem.asset.metadata as! [AVMetadataItem]


    for item in metadataList {
        if let stringValue = item.value {
           println(item.commonKey)
            if item.commonKey == "title" {
                trackLabel.text = stringValue as? String
            }
            if item.commonKey  == "artist" {
                artistLabel.text = stringValue as? String
            }
            if item.commonKey  == "artwork" {
                if let audioImage = UIImage(data: item.value as! NSData) {
                    let audioArtwork = MPMediaItemArtwork(image: audioImage)
                    println(audioImage.description)
                }
           }


        }
    }
}
@IBAction func pause(sender: AnyObject) {

    player.pause()
}
@IBAction func stop(sender: AnyObject) {

    player.stop()
    player.currentTime = 0;
}
@IBAction func sliderChanged(sender: AnyObject) {

    player.volume = sliderValue.value

}

override func viewDidLoad() {
    super.viewDidLoad()

             var error:NSError? = nil

    player = AVAudioPlayer(contentsOfURL: audioPath!, error: &error)

    player.volume = 0.5;

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}


}

这是我的示例.mp3文件的屏幕截图.如您所见，确实有相册插图在Finder的获取信息"部分中都可见.我还打开了iTunes中的.mp3，以确保并确认它的获取信息"部分以及艺术品"选项卡下是否存在艺术品.

Here is a screen shot of my sample .mp3 file. As you can see there is indeed album artwork that is both visible in the "get info" section of Finder. I've also opened the .mp3 in my iTunes to make sure and have confirmed there is artwork in the "get info" section of it there as well as under the "artwork" tab.

但是，当尝试使用commonKey将图像分配给我的imageView时，我发现没有"artwork"的commonKey.

However, when trying to use the commonKey to assign the image to my imageView I find that there is no commonKey for "artwork".

谢谢

推荐答案

将您的代码段更改为此(我已经测试过):

Change your snippet of code into this (I already tested it):

我在感兴趣的地方添加了println行注释，请随时取消注释以查看发生了什么.

I added println lines commented in places of interest, Feel free to uncomment in order to see what is happening.

   for item in metadataList {
        if item.commonKey == nil{
            continue
        }

        if let key = item.commonKey, let value = item.value {
            //println(key)
            //println(value)
            if key == "title" {
                trackLabel.text = value as? String
            }
            if key  == "artist" {
                artistLabel.text = value as? String
            }
            if key == "artwork" {
                if let audioImage = UIImage(data: value as! NSData) {
                  //println(audioImage.description)
                    artistImage.image = audioImage
                }
            }
        }
    }

更新:对该代码进行一些清理

for item in metadataList {

    guard let key = item.commonKey, let value = item.value else{
        continue
    }

   switch key {
    case "title" : trackLabel.text = value as? String
    case "artist": artistLabel.text = value as? String
    case "artwork" where value is NSData : artistImage.image = UIImage(data: value as! NSData)
    default:
      continue
   }
}

更新:对于Swift 4

for item in metadataList {

    guard let key = item.commonKey?.rawValue, let value = item.value else{
        continue
    }

   switch key {
    case "title" : trackLabel.text = value as? String
    case "artist": artistLabel.text = value as? String
    case "artwork" where value is Data : artistImage.image = UIImage(data: value as! Data)
    default:
      continue
   }
}

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