android - java.lang.NoSuchMethodError : No virtual method getMicrophones() 错误

Question

我有这个非常简单的枚举设备上的所有麦克风

public class MainActivity
      extends AppCompatActivity
{
   private static String TAG = MainActivity.class.getSimpleName();
   @Override
   protected void onCreate(Bundle savedInstanceState)
   {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      AudioManager audioManager =
            (AudioManager) getSystemService(Context.AUDIO_SERVICE);
      List<MicrophoneInfo> mics = null;
      try
      {
         mics = audioManager.getMicrophones();
      }
      catch ( IOException e )
      {
         e.printStackTrace();
      }
      Log.d(TAG,"mics.size() = "+ mics.size());
      for(MicrophoneInfo mic : mics)
      {

      }
   }
}

但是当我在我的任何设备上运行应用程序时，我得到

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.micsrc, PID: 8721
    java.lang.NoSuchMethodError: No virtual method getMicrophones()Ljava/util/List; 
    in class Landroid/media/AudioManager; or its super classes (declaration 
    of 'android.media.AudioManager' appears in /system/framework/framework.jar)
        at com.example.micsrc.MainActivity.onCreate(MainActivity.java:27)
        at android.app.Activity.performCreate(Activity.java:6285)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1108)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2408)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2541)
        at android.app.ActivityThread.access$900(ActivityThread.java:169)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1382)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:148)
        at android.app.ActivityThread.main(ActivityThread.java:5554)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:746)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:636)

Answer 1

你需要处理向后兼容:

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
    List<MicrophoneInfo> mics = am.getMicrophones();
    ...
} else {
    AudioDeviceInfo[] deviceInfo = am.getDevices(AudioManager.GET_DEVICES_INPUTS);
    ...
}

“耳机”连接器不是麦克风 - 但对于双工耳机，它仍可能连接有麦克风……即使可能无法直接检测到该麦克风。 BT 耳机甚至扬声器也可能配备麦克风，这需要从 A2DP 接收器查询。