近期在项目中须要对外部存储设备的状态进行监听，所以整理了此笔记，以便日后查看。

外部存储设备的状态变化时发出的广播

对照不同状态下的广播

1. 插入外部SD卡时：

2. 移除外部SD卡时：

3. 连接PC进入USB大容量存储模式时：

4. 连接PC退出USB大容量存储模式时：

代码实现监听

public void startListen()

{

    IntentFilter intentFilter = new IntentFilter(Intent.ACTION_MEDIA_MOUNTED);

    intentFilter.setPriority(1000);

    intentFilter.addAction(Intent.ACTION_MEDIA_UNMOUNTED);

    intentFilter.addAction(Intent.ACTION_MEDIA_REMOVED);

    intentFilter.addAction(Intent.ACTION_MEDIA_SHARED);

    intentFilter.addAction(Intent.ACTION_MEDIA_BAD_REMOVAL);

    intentFilter.addAction(Intent.ACTION_MEDIA_SCANNER_STARTED);

    intentFilter.addAction(Intent.ACTION_MEDIA_SCANNER_FINISHED);

    intentFilter.addAction(Intent.ACTION_MEDIA_CHECKING);

    intentFilter.addAction(Intent.ACTION_MEDIA_EJECT);

    intentFilter.addAction(Intent.ACTION_MEDIA_NOFS);

    intentFilter.addAction(Intent.ACTION_MEDIA_BUTTON);

    intentFilter.addAction(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);

    intentFilter.addDataScheme("file");

    registerReceiver(broadcastRec, intentFilter);

}

private final BroadcastReceiver broadcastRec = new BroadcastReceiver() {

    @Override

    public void onReceive(Context context, Intent intent) {

        String action = intent.getAction();

        Log.d("MediaAction", action);

        if (action.equals("android.intent.action.MEDIA_MOUNTED"))

        {

        	//todo

        } else if (action.equals(Intent.ACTION_MEDIA_UNMOUNTED))

        {

        	//todo

        }else if (action.equals(Intent.ACTION_MEDIA_SCANNER_STARTED)){

        }else if (action.equals(Intent.ACTION_MEDIA_SCANNER_FINISHED)){

        }else if (action.equals(Intent.ACTION_MEDIA_SHARED)){

        }else {

        }

    }

};