當用戶在AndroidStudioKotlin中切換到其他頁面時，如何停止播放音樂？

我創建了一個冥想應用程式，用戶可以從片段內的回收器視圖中選擇他們想要的類，然后它將顯示新活動中的詳細內容和步驟。在新活動中，我實作了一個音頻播放功能，用戶可以在其中從 firebase 流式傳輸音頻檔案。現在的問題是，每當我切換回片段中的回收器視圖時，音頻檔案仍會在后臺播放。每當我切換到應用程式內的另一個頁面或切換到另一個應用程式時，如何停止播放音頻檔案？

這是片段中回收者??視圖的代碼

class ClassFragment : Fragment() {

private lateinit var recyclerView: RecyclerView
private lateinit var classArrayList: ArrayList<Classes>
private lateinit var tempArraylist: ArrayList<Classes>
private lateinit var classAdapter: ClassAdapter
private lateinit var db: FirebaseFirestore
var mediaPlayer: MediaPlayer? = null

override fun onCreateView(
    inflater: LayoutInflater, container: ViewGroup?,
    savedInstanceState: Bundle?
): View? {
    val view: View = inflater.inflate(R.layout.fragment_class, container, false)
    recyclerView = view.findViewById(R.id.ClassList)
    recyclerView.layoutManager = LinearLayoutManager(context)
    recyclerView.setHasFixedSize(true)

    classArrayList = arrayListOf()
    tempArraylist = arrayListOf()
    eventChangeListener()
    classAdapter = ClassAdapter(requireContext(), classArrayList)

    recyclerView.adapter = classAdapter

    return view
}


private fun eventChangeListener() {
    db = FirebaseFirestore.getInstance()
    db.collection("class").addSnapshotListener(object : EventListener<QuerySnapshot> {
        override fun onEvent(value: QuerySnapshot?, error: FirebaseFirestoreException?) {
            if (error != null) {
                Log.e("Firestore error", error.message.toString())
                return
            }
            for (dc: DocumentChange in value?.documentChanges!!) {
                if (dc.type == DocumentChange.Type.ADDED) {

                    classArrayList.add(
                        dc.document.toObject(
                            (Classes::class.java)
                        )
                    )
                }
            }
            tempArraylist.clear()
            tempArraylist.addAll(classArrayList)
            classAdapter.notifyDataSetChanged()
        }
    })
}

}

這是新活動頁面的代碼，當用戶從 recyclerview 中選擇時，它將顯示內容

class DetailActivity : AppCompatActivity() {

private lateinit var imageViewClass: ImageView
private lateinit var textViewClassName: TextView
private lateinit var textViewClassDes: TextView
private lateinit var textViewClassContent: TextView
private var stop:Boolean = false
var mediaPlayer: MediaPlayer? = null
override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_detail)
    val btnPlay: Button = findViewById(R.id.btnPlay)
    val btnStop: Button = findViewById(R.id.btnStop)


    imageViewClass = findViewById(R.id.imageViewClassImage)
    textViewClassName = findViewById(R.id.textViewClassName)
    textViewClassDes = findViewById(R.id.textViewClassDescription)
    textViewClassContent = findViewById(R.id.textViewClassContent)


    val classImage = intent.getStringExtra("class_image")
    val className = intent.getStringExtra("class_name")
    val classDes = intent.getStringExtra("class_des")
    val classContent = intent.getStringExtra("class_content")
    val classAudio = intent.getStringExtra("class_audio")

    Glide.with(this)
        .load(classImage)
        .centerCrop()
        .into(imageViewClass)
    textViewClassName.text = className
    textViewClassDes.text = classDes
    textViewClassDes.text = classDes!!.replace("\\n", "\n")
    textViewClassContent.text = classContent
    textViewClassContent.text = classContent!!.replace("\\n", "\n")

    btnPlay.isEnabled = true
    btnStop.isEnabled = false

    btnPlay.setOnClickListener(object : View.OnClickListener {
        override fun onClick(v: View?) {
            if (mediaPlayer == null) {
                mediaPlayer = MediaPlayer.create(this@DetailActivity, Uri.parse(classAudio))
                mediaPlayer!!.isLooping = true
                mediaPlayer!!.start()
                btnStop.isEnabled = true
                btnPlay.isEnabled = false
                Toast.makeText(applicationContext,"Audio Starts",Toast.LENGTH_SHORT).show()
            } else mediaPlayer!!.start()

        }

    })

    mediaPlayer?.setOnCompletionListener {
        btnPlay.isEnabled = true
        btnStop.isEnabled = false
        Toast.makeText(this,"end",Toast.LENGTH_SHORT).show()
    }

    btnStop.setOnClickListener(object : View.OnClickListener {
        override fun onClick(v: View?) {
            if(mediaPlayer!!.isPlaying){
                stop = false
                mediaPlayer!!.stop()
                mediaPlayer!!.reset()
                mediaPlayer!!.release()
                mediaPlayer = null
                btnPlay.isEnabled = true
                btnStop.isEnabled = false
                Toast.makeText(applicationContext,"Audio Stops",Toast.LENGTH_SHORT).show()
            }
        }
    })
}
}

uj5u.com熱心網友回復：

這是一個經典案例onDestroy中的Activity所謂的幸福。我會保持簡短，但有一個生命周期Activity，當您似乎從 SecondActivity 回傳到第一個 Activity 時，onDestroy您的第二個 Activity 的 被呼叫來執行銷毀功能

所以解決方案，覆寫onDestroy你的DetailActivity類中的方法并做這樣的事情

override fun onDestroy(){
 if(mediaPlayer != null){
   mediaPlayer!!.stop()
   mediaPlayer!!.reset()
   mediaPlayer!!.release()
   mediaPlayer = null
 }
}

您可以詳細閱讀Activity Lifecyle

標籤：安卓 安卓工作室 科特林 安卓音乐播放器

上一篇：如何在顫振中創建雙復選框

下一篇：關于android上JNI中C 全域變數的問題