Question

我正在开发一个耳部训练应用程序，希望让用户决定要识别的声音类型（不同的乐器，合成声音等）

因此，作为“虚拟声音”，我会在SoundPool中加载类似声纳的ping：

open class PingSoundPool(context: Context) {

    open var mAttributes = AudioAttributes.Builder()
        .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
        .setUsage(AudioAttributes.USAGE_GAME)
        .build()

    open var mSoundPool = SoundPool.Builder()
        .setMaxStreams(9)
        .setAudioAttributes(mAttributes)
        .build()

    open var babping = mSoundPool.load(context, R.raw.ab830ping, 1)
    open var aaping = mSoundPool.load(context, R.raw.a220ping, 1)
    open var abbping = mSoundPool.load(context, R.raw.bb233ping, 1)
    open var abping = mSoundPool.load(context, R.raw.b247ping, 1)
[and others]

open fun loadPings(note: Int) {
    println(note.toString())
    if (note == 0) {}
    if(note == 1)
        mSoundPool.play(acping, 2.55f, 2.55f, 1, 0, 1f)
    if(note == 2)
    mSoundPool.play(adbping, 2.5f, 2.5f, 1, 0, 1f)
    if(note == 3)
        mSoundPool.play(adping, 2.45f, 2.45f, 1, 0, 1f)
    if(note == 4)
        mSoundPool.play(aebping, 2.4f, 2.4f, 1, 0, 1f)
[and so on]
}

现在，我可以在自己的活动中访问它了

companion object {
    lateinit var pingSoundPool: PingSoundPool
}

然后在onCreate中进行pingSoundPool = PingSoundPool(this)

像这样，我可以使用FullscreenActivity.pingSoundPool.loadPings(note: Int)

播放任何声音

现在，当我想更改声音时出现问题。第一步是创建一个首选项，给我一个带有所需声音的弦（“砰”，“乒乓”，“长笛”，“小提琴”等）。第二步是获取所述字符串并相应地加载SoundPool。

现在，如果我尝试放这个-

val sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context)
val pingsound = sharedPreferences.getString("pingsound", "")

if(pingsound == "ping"){
    open var babping = mSoundPool.load(context, R.raw.ab830ping, 1)
    open var aaping = mSoundPool.load(context, R.raw.a220ping, 1)
    open var abbping = mSoundPool.load(context, R.raw.bb233ping, 1)
    open var abping = mSoundPool.load(context, R.raw.b247ping, 1)
[etc]
}

在我的SoundPool类中，收到一条错误消息，“正在期待成员声明。” /“函数声明必须具有名称。”

如果相反，我只是复制整个课程的内容，然后像这样新建一个课程

class PongSoundPool(context: Context): PingSoundPool(context) {

    override var mAttributes = AudioAttributes.Builder()
        .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
        .setUsage(AudioAttributes.USAGE_GAME)
        .build()

    override var mSoundPool = SoundPool.Builder()
        .setMaxStreams(9)
        .setAudioAttributes(mAttributes)
        .build()

    open var babping = mSoundPool.load(context, R.raw.ab830pong, 1)
    open var aaping = mSoundPool.load(context, R.raw.a220pong, 1)
    open var abbping = mSoundPool.load(context, R.raw.bb233pong, 1)
    open var abping = mSoundPool.load(context, R.raw.b247pong, 1)

并在这样的活动中分配pingSoundPool的值

        val sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this)
        val pingsound = sharedPreferences.getString("pingsound", "")

        when (pingsound) {
        "ping" -> pingSoundPool = PingSoundPool(this)
        "pong" -> pingSoundPool = PongSoundPool(this)
    }

然后，一旦我将首选项更改为“ pong”，就什么也没有发生。重新启动应用程序时，出现运行时错误：

    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example/com.example.FullscreenActivity}: java.lang.IllegalArgumentException: Invalid null AudioAttributes
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2817)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892)
    at android.app.ActivityThread.-wrap11(Unknown Source:0)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1593)
    at android.os.Handler.dispatchMessage(Handler.java:105)
    at android.os.Looper.loop(Looper.java:164)
    at android.app.ActivityThread.main(ActivityThread.java:6541)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
 Caused by: java.lang.IllegalArgumentException: Invalid null AudioAttributes
    at android.media.SoundPool$Builder.setAudioAttributes(SoundPool.java:601)
    at com.example.PingSoundPool.<init>(PingSoundPool.kt:16)
    at com.example.PongSoundPool.<init>(PongSoundPool.kt:7)
    at com.example.FullscreenActivity.onCreate(FullscreenActivity.kt:97)
    at android.app.Activity.performCreate(Activity.java:6975)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1213)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2770)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892) 
    at android.app.ActivityThread.-wrap11(Unknown Source:0) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1593) 
    at android.os.Handler.dispatchMessage(Handler.java:105) 
    at android.os.Looper.loop(Looper.java:164) 
    at android.app.ActivityThread.main(ActivityThread.java:6541) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)

它在PingSoundPool中指向的行是：.setAudioAttributes(mAttributes)

现在我不知道如何实现此目的。有人得到帮助了吗？

Answer 1

您的第一次崩溃是由于不正确的继承。如果您已经在var mAttributes中实现了PingSoundPool和var mSoundPool，请不要在PongSoundPool上覆盖它。另外，您可以通过不将PingSoundPool创建为父类来改善体系结构。但是BaseSoundPool具有最终属性mAttributes和mSoundPool，并且具有抽象方法fun play(note: Int)

abstract class BaseSoundPool(val context: Context) {

    protected var loadedSoundChannels: IntArray? = null

    private val attributes = AudioAttributes.Builder()
        .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
        .setUsage(AudioAttributes.USAGE_GAME)
        .build()

    final val soundPool = SoundPool.Builder()
        .setMaxStreams(9)
        .setAudioAttributes(attributes)
        .build()

    fun load(rawSoundIds: IntArray) {
        loadedSoundChannels?.run { unload(this) } // todo implement unload fun by yourself
        loadedSoundChannels = IntArray(rawSoundIds.size) {
            soundPool.load(context, rawSoundIds[it], 1)
        }
    }

    abstract fun play(note: Int)
}

class PingSoundPool(context: Context) : BaseSoundPool(context) {
    override fun play(note: Int) {
        loadedSoundChannels?.getOrNull(note)?.let {
            soundPool.play(note, 1f, 1f, 1, 0, 1f);
        }
    }
}

还要记住，SoundPool.load是异步操作，因此您不能在加载后立即调用播放。同样，在加载新的声音数据时，还应该卸载以前加载的声音。也许您会发现我对SoundPool的实现很有用，这在不同的API上更容易预测。

如何更改SoundPool

1 个答案: