如何傳遞字符串數組以查看 model 以在 swiftUI 中播放歌曲

Question

我創建了一個 model 並添加了嵌套結構。 根據結構詳細信息之一創建了一個數組，我想從 Model 中檢索詳細信息以查看 model 以播放音樂。

我想檢索這個“aURL”字符串並將其插入到播放 function 中以播放音樂。

class myViewModel: ObservableObject {
@Published var isPlaying = false
var player = AVAudioPlayer()

func play(){
    do{
        player = try AVAudioPlayer(contentsOf: Array[0] as URL )
        if player.isPlaying{player.pause()}
        else{player.play()}
        isPlaying = player.isPlaying
        
    }catch{print("error")}
}
}

Answer 1

制作var feelSongs: [myModel.MA]到 static 之類的

static var feelSongs: [myModel.M.A] 

並像這樣在視圖 model 內使用它

class MyViewModel: ObservableObject {
    @Published var isPlaying = false
    var player = AVAudioPlayer()
    var arrData = myModel.M.feelSongs
    func play(with url: URL?){
        guard let url = url else {
            return
        }
        do{
            player = try AVAudioPlayer(contentsOf: url )
            if player.isPlaying{player.pause()}
            else{player.play()}
            isPlaying = player.isPlaying
            
        }catch{print("error")}
    }
}

注意： Class 名稱和結構名稱以大寫字母開頭。

Answer 2

你的結構嵌套在結構中嵌套在結構中很奇怪，反正我不知道你的想法。

請測試一下：

class MyModel: Codable {

    var feelSongs: [MyModel.M.A] = [
        MyModel.M.A.init(id: 1, afcontent: "Feeling Happy", aURL: "a1.mp3", isOn: true),
        MyModel.M.A.init(id: 2, afcontent: "Feeling Sad", aURL: "a2.mp3", isOn: true),
        MyModel.M.A.init(id: 3, afcontent: "Feeling Positive", aURL: "a3.mp3", isOn: true),
        MyModel.M.A.init(id: 4, afcontent: "Feeling Healthy", aURL: "a4.mp3", isOn: true)
    ]
    struct M: Codable{
        var mURL: String
        var bgMusic : String
        var bgVol : Double

        struct A : Codable, Identifiable {
            var id : Int
            var afcontent : String
            var aURL : String
            var isOn : Bool
            
            
        }
    }
}


class MyViewModel: ObservableObject {
    @Published var isPlaying = false
    var player = AVAudioPlayer()

    var theModel = MyModel()
    
    **//ADDED THIS**
    var playNow = 0

    func play(){

        if playNow >= theModel.feelSongs.count {
            return
        }
        let url = theModel.feelSongs[playNow]
        guard let url = URL(string: url) else {
            return
        }
        
        **//ADDED THIS**
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "playerDidFinishPlaying:", name: AVPlayerItemDidPlayToEndTimeNotification, object: item) 
        do {
            player = try AVAudioPlayer(contentsOf: url )
            if player.isPlaying{player.pause()}
            else{player.play()}
            isPlaying = player.isPlaying

        }
        catch{print("error")}
    }

    **//ADDED THIS**
    func playerDidFinishPlaying(note: NSNotification) {
        play()
    }
}
//
struct ContentView: View {
    var mymodel = MyViewModel()
    
    var body: some View {
        //Text("3")
        List(mymodel.theModel.feelSongs) { song in
            Text(song.afcontent)                    
        }
        .onAppear {
             mymodel.play()
        }
    }
}



struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}