listener for sd-card removal

im trying to do something similar to this: android: how to listen to "sd card removed unexpectedly" but onReceive of the listener never gets called, when i dont have sdcard mounted or i remove the sdcard. Here is the code.

public class MyClass1  extends Activity{
    BroadcastReceiver mSDCardStateChangeListener = null;
     /** Called when the activity is first created. */
    public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    mSDCardStateChangeListener = MyClass2.registerSDCardStateChangeListener(this);
   //some code which needs SDCard开发者_如何学运维 and throws unhandled exception if sdcard is not there 

}

@Override 
    protected void onDestroy () 
    {
        MyClass2.unRegisterSDCardStateChangeListener(this, mSDCardStateChangeListener);
        super.onDestroy();
    }



//in MyClass2
public static BroadcastReceiver registerSDCardStateChangeListener(Activity act) {

        BroadcastReceiver mSDCardStateChangeListener = new BroadcastReceiver() {

            @Override
            public void onReceive(Context arg0, Intent arg1) {
                 String action = arg1.getAction();
                    if(action.equalsIgnoreCase(Intent.ACTION_MEDIA_REMOVED)
                            || action.equalsIgnoreCase(Intent.ACTION_MEDIA_UNMOUNTED)
                            || action.equalsIgnoreCase(Intent.ACTION_MEDIA_BAD_REMOVAL)
                            || action.equalsIgnoreCase(Intent.ACTION_MEDIA_EJECT)) 
                    {
                        //i never come here ;(
                    //do something

                    }

            }
        };
        IntentFilter filter = new IntentFilter();
        filter.addAction(Intent.ACTION_MEDIA_REMOVED);
        filter.addAction(Intent.ACTION_MEDIA_UNMOUNTED);
        filter.addAction(Intent.ACTION_MEDIA_BAD_REMOVAL);
        filter.addAction(Intent.ACTION_MEDIA_EJECT);
        filter.addDataScheme("file");
        act.registerReceiver(mSDCardStateChangeListener, filter);
        return mSDCardStateChangeListener;
 }

public static void unRegisterSDCardStateChangeListener(Activity act, BroadcastReceiver mSDCardStateChangeListener)
     {
         act.unregisterReceiver(mSDCardStateChangeListener);
     }

i do not want to check if sdcard is present or not by if(android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED)) but use receiver instead. Any help is welcome.Thanks!.

Ok I think the code I posted is meant for the action & not the state & works fine.

from documentation:

android.content.Intent.ACTION_MEDIA_REMOVED Broadcast Action: External media has been removed. The path to the mount point for the removed media is contained in the Intent.mData field.

so what I was expecting(I was wrong, see the first two lines of the Question) that if i dont have SDCard(i.e. it has been removed earlier) and then I launch the app I would get the call implying that I dont have the SDCard (I know sounds stpid ;)) . The intent are actions(and not state).So If I remove the sdcard while the app is active I do receive the callback. Thanks for your time Vegas.