android 中如何监听耳机键消息

在研究一个功能：如何通过耳机键来拍照/摄像，好处自不用多说了，拍照时可以防抖

那么这引出一个问题，如何在 Camera/VideoCamera Activity中监听耳机键。

耳机键在 android 中的定义为

/** Key code constant: Headset Hook key.
* Used to hang up calls and stop media. */
public static final int KEYCODE_HEADSETHOOK = 79;

主要用来接听/挂断电话，播放/暂停音乐视频等

监听耳机键有两种方式：

1，直接在 Activity的onKeyDown 或 onKeyUp 函数中添加对应的 case 即可

    @Override    public boolean onKeyUp(int keyCode, KeyEvent event) {        switch (keyCode) {……case KeyEvent.KEYCODE_HEADSETHOOK://add your code here……        }        return super.onKeyUp(keyCode, event);    }

2，注册 BroadcastReceiver 来响应该按键

//  listener media buttonprivate BroadcastReceiver mMediaButtonReceiver = null;private class MediaButtonBroadcastReceiver extends BroadcastReceiver {    @Override public void onReceive(Context context, Intent intent) { Log.v(TAG," call MediaButtonBroadcastReceiver"); KeyEvent event = (KeyEvent) intent.getParcelableExtra(Intent.EXTRA_KEY_EVENT); Log.v(TAG, " event "+event); if ((event != null)&& (event.getKeyCode() == KeyEvent.KEYCODE_HEADSETHOOK)) {Toast.makeText(VideoCamera.this, R.string.hook, Toast.LENGTH_SHORT).show(); }  } } //registerReceiverIntentFilter mediaButtonIntentFilter = new IntentFilter();mediaButtonIntentFilter.addAction(Intent.ACTION_MEDIA_BUTTON);mMediaButtonReceiver = new MediaButtonBroadcastReceiver();registerReceiver(mMediaButtonReceiver, mediaButtonIntentFilter); //unregisterReceiverif (mMediaButtonReceiver != null){unregisterReceiver(mMediaButtonReceiver);mMediaButtonReceiver = null;}

更多相关文章

随机推荐