audio - android上声音播放器的修改

Question

我正在尝试制作一个简单的钢琴应用程序。我找到了这个教程；http://www.martinhoeller.net/2012/01/13/developing-a-musical-instrument-app-for-android/。

我在此链接上下载了文件并将其导入。我运行该应用程序，上面有 4 个按钮，可以播放加载在资产文件中的 4 个不同的音符。

然后我尝试修改这个项目来制作一个钢琴应用程序。

起初我从 xml 中删除了这些红色按钮。

我在背景中添加了钢琴图像。

然后我在每个键上创建了按钮。

xml文件是；

  <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_gravity="fill_vertical"
    android:background="@drawable/images"
    android:orientation="vertical" >

    <Button
        android:id="@+id/buttonC4"
        android:layout_width="294dp"
        android:layout_height="60dp"
        android:background="@android:color/transparent"
        android:gravity="center_vertical|center_horizontal" />

    <Button
        android:id="@+id/buttonD4"
        android:layout_width="294dp"
        android:layout_height="60dp"
        android:background="@android:color/transparent"
        android:gravity="center_vertical|center_horizontal" />

    <Button
        android:id="@+id/buttonE4"
        android:layout_width="294dp"
        android:layout_height="60dp"
        android:background="@android:color/transparent"
        android:gravity="center_vertical|center_horizontal" />

    <Button
        android:id="@+id/buttonF4"
        android:layout_width="294dp"
        android:layout_height="58dp"
        android:background="@android:color/transparent"
        android:gravity="center_vertical|center_horizontal" />


    <Button
        android:id="@+id/buttonG4"
        android:layout_width="294dp"
        android:layout_height="58dp"
        android:background="@android:color/transparent"
        android:gravity="center_vertical|center_horizontal" />

    <Button
        android:id="@+id/buttonA4"
        android:layout_width="294dp"
        android:layout_height="60dp"
        android:background="@android:color/transparent"
        android:gravity="center_vertical|center_horizontal" />

    <Button
        android:id="@+id/buttonB4"
        android:layout_width="294dp"
        android:layout_height="58dp"
        android:background="@android:color/transparent"
        android:gravity="center_vertical|center_horizontal" />

    <Button
         android:id="@+id/buttonC5"
        android:layout_width="294dp"
        android:layout_height="58dp"
        android:background="@android:color/transparent"
        android:gravity="center_vertical|center_horizontal" />

    <Button
        android:id="@+id/buttonD5"
        android:layout_width="294dp"
        android:layout_height="58dp"
        android:background="@android:color/transparent"
        android:gravity="center_vertical|center_horizontal" />


    <Button
        android:id="@+id/buttonE5"
        android:layout_width="294dp"
        android:layout_height="58dp"
        android:background="@android:color/transparent"
        android:gravity="center_vertical|center_horizontal" />

</LinearLayout>

然后我在互联网上找到了笔记并下载了它们。

我将这些注释文件上传到资产文件夹。

它们中的每一个都是 wav 格式。

然后我将这些代码添加到 PianoTest Activity ；

  buttons = new ArrayList<View>();
 buttons.add(findViewById(R.id.buttonC4));
 buttons.add(findViewById(R.id.buttonD4));
 buttons.add(findViewById(R.id.buttonF4));
 buttons.add(findViewById(R.id.buttonG4));
 buttons.add(findViewById(R.id.buttonA4));
 buttons.add(findViewById(R.id.buttonB4));
 buttons.add(findViewById(R.id.buttonC5));
 buttons.add(findViewById(R.id.buttonD5));
 buttons.add(findViewById(R.id.buttonE5));

然后我修改了这个功能；

private void toggleButtonSound(View button, boolean down) { String note = null;

switch (button.getId())
{
    case R.id.buttonC4:
        note = "C4";
        break;

    case R.id.buttonD4:
        note = "D4";
        break;
    case R.id.buttonE4:
        note = "E4";
        break;

    case R.id.buttonF4:
        note = "F4";
        break;

    case R.id.buttonG4:
        note = "G4";
        break;
    case R.id.buttonA4:
        note = "A4";
        break;

    case R.id.buttonB4:
        note = "B4";
        break;

    case R.id.buttonC5:
        note = "C5";
        break;

    case R.id.buttonD5:
        note = "D5";
        break;
    case R.id.buttonE5:
        note = "E5";
        break;
}

然后我改变了 AudioTrack 类。我将格式更改为 wav 文件；

public void run()
    {
        try
        {
            String path = note + ".wav";

其他一切都与原始项目中的相同。

但该应用程序无法正常工作。

当我运行该应用程序并单击一个键上的透明按钮时，它会播放声音，但它与原来的声音不同。

听起来有些不同。我可以说是电子版的音符。

当我单击其他一些键时，应用程序崩溃。它说应用程序意外停止。

怎么了 ？我应该怎么做才能让它工作？原因可能是我下载的文件。我需要找到什么样的笔记？该项目的比特或持续时间是否有任何特殊格式？

这对我来说非常重要，如果你可以从链接下载文件并运行，你可以看到它是如何工作的。你可以建议我修改它的方法。我希望你能帮助我。这是日志猫：

05-13 19:49:55.580: D/AndroidRuntime(485): Shutting down VM
05-13 19:49:55.580: W/dalvikvm(485): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
05-13 19:49:55.600: E/AndroidRuntime(485): FATAL EXCEPTION: main
05-13 19:49:55.600: E/AndroidRuntime(485): java.lang.RuntimeException: Unable to start activity ComponentInfo{net.martinhoeller/net.martinhoeller.PianoTestActivity}: android.view.InflateException: Binary XML file line #9: Error inflating class ButtonView
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.app.ActivityThread.access$2300(ActivityThread.java:125)
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.os.Handler.dispatchMessage(Handler.java:99)
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.os.Looper.loop(Looper.java:123)
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.app.ActivityThread.main(ActivityThread.java:4627)
05-13 19:49:55.600: E/AndroidRuntime(485):  at java.lang.reflect.Method.invokeNative(Native Method)
05-13 19:49:55.600: E/AndroidRuntime(485):  at java.lang.reflect.Method.invoke(Method.java:521)
05-13 19:49:55.600: E/AndroidRuntime(485):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
05-13 19:49:55.600: E/AndroidRuntime(485):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
05-13 19:49:55.600: E/AndroidRuntime(485):  at dalvik.system.NativeStart.main(Native Method)
05-13 19:49:55.600: E/AndroidRuntime(485): Caused by: android.view.InflateException: Binary XML file line #9: Error inflating class ButtonView
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:576)
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.view.LayoutInflater.rInflate(LayoutInflater.java:618)
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.view.LayoutInflater.inflate(LayoutInflater.java:407)
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.view.LayoutInflater.inflate(LayoutInflater.java:320)
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.view.LayoutInflater.inflate(LayoutInflater.java:276)
05-13 19:49:55.600: E/AndroidRuntime(485):  at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:198)
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.app.Activity.setContentView(Activity.java:1647)
05-13 19:49:55.600: E/AndroidRuntime(485):  at net.martinhoeller.PianoTestActivity.onCreate(PianoTestActivity.java:23)
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
05-13 19:49:55.600: E/AndroidRuntime(485):  ... 11 more
05-13 19:49:55.600: E/AndroidRuntime(485): Caused by: java.lang.ClassNotFoundException: android.view.ButtonView in loader dalvik.system.PathClassLoader[/data/app/net.martinhoeller-1.apk]
05-13 19:49:55.600: E/AndroidRuntime(485):  at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:243)
05-13 19:49:55.600: E/AndroidRuntime(485):  at java.lang.ClassLoader.loadClass(ClassLoader.java:573)
05-13 19:49:55.600: E/AndroidRuntime(485):  at java.lang.ClassLoader.loadClass(ClassLoader.java:532)
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.view.LayoutInflater.createView(LayoutInflater.java:466)
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.view.LayoutInflater.onCreateView(LayoutInflater.java:544)
05-13 19:49:55.600: E/AndroidRuntime(485):  at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:66)
05-13 19:49:55.600: E/AndroidRuntime(485):  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:563)
05-13 19:49:55.600: E/AndroidRuntime(485):  ... 20 more
05-13 19:52:22.293: D/AndroidRuntime(513): Shutting down VM
05-13 19:52:22.293: W/dalvikvm(513): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
05-13 19:52:22.309: E/AndroidRuntime(513): FATAL EXCEPTION: main
05-13 19:52:22.309: E/AndroidRuntime(513): java.lang.ArrayIndexOutOfBoundsException
05-13 19:52:22.309: E/AndroidRuntime(513):  at net.martinhoeller.PianoTestActivity.onTouchEvent(PianoTestActivity.java:66)
05-13 19:52:22.309: E/AndroidRuntime(513):  at android.app.Activity.dispatchTouchEvent(Activity.java:2089)
05-13 19:52:22.309: E/AndroidRuntime(513):  at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1655)
05-13 19:52:22.309: E/AndroidRuntime(513):  at android.view.ViewRoot.handleMessage(ViewRoot.java:1785)
05-13 19:52:22.309: E/AndroidRuntime(513):  at android.os.Handler.dispatchMessage(Handler.java:99)
05-13 19:52:22.309: E/AndroidRuntime(513):  at android.os.Looper.loop(Looper.java:123)
05-13 19:52:22.309: E/AndroidRuntime(513):  at android.app.ActivityThread.main(ActivityThread.java:4627)
05-13 19:52:22.309: E/AndroidRuntime(513):  at java.lang.reflect.Method.invokeNative(Native Method)
05-13 19:52:22.309: E/AndroidRuntime(513):  at java.lang.reflect.Method.invoke(Method.java:521)
05-13 19:52:22.309: E/AndroidRuntime(513):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
05-13 19:52:22.309: E/AndroidRuntime(513):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
05-13 19:52:22.309: E/AndroidRuntime(513):  at dalvik.system.NativeStart.main(Native Method)

Answer 1

你似乎有很多问题。让我们先尝试修复布局膨胀崩溃。

List<Button> buttons;
...
buttons = new ArrayList<Button>();
buttons.add((Button)findViewById(R.id.buttonC4));
buttons.add((Button)findViewById(R.id.buttonD4));
...
for (Button button : buttons) {
    button.setOnClickListener(this);
}

这将正确地转换您的布局的按钮视图并为每个视图设置一个 OnClickListener。
您的活动将需要implement View.OnClickListener使用setOnClickListener(this). 如果您将点击处理分开，则替换为适当的类，implement OnClickListener在这种情况下，该类将代替您的 Activity。