在Nexus 7 Marshmallow上初始化AudioRecorder

Question

I have a program that's been running successfully on half a dozen test devices, and hundreds of apparently happy users who download my app from Google Play.

I bought a used Nexus 7 that has been upgraded to Marshmallow, and I can't record. The device runs other sound-recording apps just fine, but it just won't run my app.

Here's some code:

private static AudioRecord recorder = null;

public static void record() throws IllegalArgumentException
{
    int channelConfig = AudioFormat.CHANNEL_IN_MONO;
    int audioFormat = AudioFormat.ENCODING_PCM_16BIT;
    int sampleRate = 44100;
    int minSize = AudioRecord.getMinBufferSize(sampleRate, channelConfig, audioFormat );
    int latencySize = 3584;
    int inputBufferSize = Math.max( minSize, latencySize );
    recorder = new AudioRecord( MediaRecorder.AudioSource.DEFAULT, sampleRate, channelConfig, audioFormat, inputBufferSize );
    int state = recorder.getState();
    if ( state != AudioRecord.STATE_INITIALIZED )
    {
        if ( recorder != null )
            recorder.release();
        recorder = null;
        throw new IllegalArgumentException( "Failed to initialize Audio recorder.  State = " + state );
    }
    recorder.startRecording();
    Thread inputThread = new Thread( new Runnable() { public void run() { inputTask(); } }, "Input" );
    inputThread.setPriority( Thread.MAX_PRIORITY );
    inputThread.start();
}

This fails with state 0, which is the same as STATE_UNINITIALIZED .

My AndroidManifest.xml includes

<uses-permission android:name="android.permission.RECORD_AUDIO"/>

As I've said, this code runs successfully on hundreds of other machines, it just fails on my Nexus 7. Is there something new and different about Marshmallow? Should I suspect some glitch in my hardware? What's going on?

Answer 1

In Android 6.0 Marshmallow there has been introduced a new way to work with permissions.

Now some permissions should be asked during runtime and user can choose, allow it or not.

Check this link for more information