Android 来电监听及录音

public class MyService extends Service {

    private MediaRecorder mRecorder;
    private String num;

    @Override
    public void onCreate() {
        super.onCreate();
        TelephonyManager manager = (TelephonyManager) getSystemService(TELEPHONY_SERVICE);    // 获取电话管理器
        manager.listen(new MyPhoneStateListener(), PhoneStateListener.LISTEN_CALL_STATE);    // 监听电话状态
    }

    private class MyPhoneStateListener extends PhoneStateListener {            // 电话状态监听器
        public void onCallStateChanged(int state, String incomingNumber) {    // 在电话状态改变时执行
            switch (state) {
                case TelephonyManager.CALL_STATE_RINGING:    // 振铃
                    System.out.println("来电话了");
                    num = incomingNumber;//得到来电号码
                    break;        
                case TelephonyManager.CALL_STATE_OFFHOOK:    // 摘机
                    System.out.println("开始通话");
                    start();
                    break;    
                case TelephonyManager.CALL_STATE_IDLE:        // 空闲
                    System.out.println("挂断电话");
                    stop();
                    break;
            }
        }
    }

    public void onDestroy() {
        tm.listen(listener, PhoneStateListener.LISTEN_NONE);// 取消监听
        listener = null;
    }

private void start() {
    mRecorder = new MediaRecorder();                            // 创建媒体记录器
    mRecorder.setAudioSource(MediaRecorder.AudioSource.VOICE_CALL);       // 指定音频源(麦克风)
    mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);      // 设置输出格式(3gp)
    mRecorder.setOutputFile("/mnt/sdcard/" + num + "-" + System.currentTimeMillis() + ".3gp");    // 指定文件路径(SD卡)
    mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);       // 指定编码(AMR_NB)
    try {
        mRecorder.prepare();    // 准备
    } catch (Exception e) {
        e.printStackTrace();
    }    
    mRecorder.start();   // 开始
}

@Override
public IBinder onBind(Intent intent) {
    return null;
}

//下面是录音
private void stop() {
    if (mRecorder != null) {
        mRecorder.stop();        // 停止
        mRecorder.release();    // 释放
        mRecorder = null;        // 垃圾回收
    }
}