1.获取当前输出音频方式

API 级别 16  以后的MediaRouter API 使您能够获取一些有关当前音频和视频路由信息。


方式一：获取到的内容，耳机模式是”耳机“，扬声器模式为”手机“

public static String getCurrAudioMode(Activity activity) {
    MediaRouter mr = (MediaRouter)activity.getSystemService(Context.MEDIA_ROUTER_SERVICE);
    MediaRouter.RouteInfo ri = null;
    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.JELLY_BEAN) {
        int count = mr.getRouteCount();
        for (int i = 0; i < count; i++) {
            MediaRouter.RouteInfo routeInfo = mr.getRouteAt(i);
            Log.e("RouteInfo", routeInfo.toString());
        }
        ri = mr.getSelectedRoute(MediaRouter.ROUTE_TYPE_LIVE_AUDIO);
       return ri.getName().toString();

    } else {
        return "null";
    }
}

第二种方式：

private boolean isHeadsetExists() {
    String HEADSET_STATE_PATH = "/sys/class/switch/h2w/state";
    char[] buffer = new char[1024];
    int newState = 0;

    try {
        FileReader file = new FileReader(HEADSET_STATE_PATH);
        int len = file.read(buffer, 0, 1024);
        newState = Integer.valueOf((new String(buffer, 0, len)).trim());
    }
    catch (FileNotFoundException e) {
        Log.e("FMTest", "This kernel does not have wired headset support");
    }
    catch (Exception e) {
        Log.e("FMTest", "", e);
    }
    return newState != 0;
}

state == 0 则是耳机拔出，为扬声器模式；

state == 1 则是耳机插入，为耳机模式；

推荐第一种。

2.监听耳机插入拔出广播

第一种方式：

BroadcastReceiver mReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (action.equals(Intent.ACTION_HEADSET_PLUG)) {
            if(intent.hasExtra("state")) {
                if(intent.getIntExtra("state", 0) == 0) {
                    Toast.makeText(context, "headset not connected", Toast.LENGTH_LONG).show();
                } else if(intent.getIntExtra("state", 0) == 1) {
                    Toast.makeText(context, "headset connected", Toast.LENGTH_LONG).show();
                }
            }
        }
    }
};

state == 0 则是耳机拔出，为扬声器模式；

state == 1 则是耳机插入，为耳机模式；