android 如何在按下按钮时停止音频线程？

Question

我有一个线程使用 AudioTrack 合成一系列音符，并使用搜索栏来改变速度。

t = new Thread()
    {
        public void run()
        {
            setPriority(Thread.MAX_PRIORITY);

            int buffersize = AudioTrack.getMinBufferSize(sr, AudioFormat.CHANNEL_OUT_MONO,
                    AudioFormat.ENCODING_PCM_16BIT);

            audiotrack = new AudioTrack(AudioManager.STREAM_MUSIC, sr,
                    AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT,
                    buffersize, AudioTrack.MODE_STREAM);

            short samples[] = new short[buffersize];

            int amplitude = 10000;
            double twopi = 2*Math.PI;

            double ph = 0.0;


            audiotrack.play();
            double r = 1.0594630943593; //the 12th root of 2
            frequency=261.63;
            for(int k = 1; k<9; k++) //number of notes played
            {
                frequency*=r;
                for (int i = 0; i < 4+4*temposliderval; i++) //duration of each note, if i = 50, note duration = 12 seconds
                {

                    for (int j = 0; j < buffersize; j++)
                    {
                        samples[j] = (short) (amplitude * Math.sin(ph));
                        ph += twopi * frequency / sr;
                    }
                    audiotrack.write(samples, 0, buffersize);
                }
            }

            audiotrack.stop();
            audiotrack.release();

        }
    };


    //play button
    play = (Button)findViewById(R.id.play);
    play.setBackgroundResource(R.mipmap.play);
    play.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v)
        {
            t.start();
        }
    });







    //stop button
    stop = (Button)findViewById(R.id.stop);
    stop.setBackgroundResource(R.mipmap.stop);
    stop.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            t.interrupt();
        }
    });

我希望能够在按下停止按钮时停止音频。调用 t.interrupt() 不起作用，所以 我想知道如何在按下停止按钮时正确停止线程。 目标是能够停止随时播放音频，并在再次按下播放按钮时重新启动它。

Answer 1

最简单的方法可能是声明一个 volatile 成员变量：

private volatile boolean mStop = false;

两个线程都可以访问。您可以轮询线程内部循环内的变量并在设置时停止循环，并在按下按钮时将变量设置为 true。

Answer 2

我想通了！这个方法好像没有在其他地方列出，所以我一定很幸运：

只需将线程放入一个新方法中，然后在单击播放按钮时调用该方法，而不是尝试停止线程，只需停止音轨的音频即可：

 play = (Button)findViewById(R.id.play);
    play.setBackgroundResource(R.mipmap.play);
    play.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v)
        {
            playScale();
        }
    });







    //stop button
    stop = (Button)findViewById(R.id.stop);
    stop.setBackgroundResource(R.mipmap.stop);
    stop.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v)
        {
            audiotrack.stop();
        }
    });

现在每次按下播放按钮时，线程都会重新启动，尽管实际上并没有停止。

public void playScale()
{
    t = new Thread()
    {
        public void run()
        {
            t.setPriority(Thread.MAX_PRIORITY);

            int buffersize = AudioTrack.getMinBufferSize(sr, AudioFormat.CHANNEL_OUT_MONO,
                    AudioFormat.ENCODING_PCM_16BIT);

            audiotrack = new AudioTrack(AudioManager.STREAM_MUSIC, sr,
                    AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT,
                    buffersize, AudioTrack.MODE_STREAM);

            short samples[] = new short[buffersize];

            int amplitude = 10000;

            double twopi = 2 * Math.PI;

            double ph = 0.0;

            audiotrack.play();

            double r = 1.0594630943593; //the 12th root of 2

            frequency = 261.63;
            for (int k = 1; k < 9; k++) //number of notes played
            {
                frequency *= r;
                for (int i = 0; i < 4 + 4 * temposliderval; i++) //duration of each note, if i = 50, note duration = 12 seconds; minimum tempo = 60 bpm
                {
                    for (int j = 0; j < buffersize; j++)
                    {
                        samples[j] = (short) (amplitude * Math.sin(ph));
                        ph += twopi * frequency / sr;
                    }
                    audiotrack.write(samples, 0, buffersize);
                }
            }
        }
    };
    t.start();
}

android 如何在按下按钮时停止音频线程？

android how to stop audio thread on button press?

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audiotrack