//use Handler.obtainMessage(),instead of msg = new Message();

//because if there is already an Message object,that not be used by

//any one ,the system will hand use that object,so you don't have to

//create and object and allocate memory.

//it  is also another example of object recycling and reusing in android.

    Message msg = mHandler.obtainMessage();

    msg.what = UPDATE_LISTVIEW;

    msg.obj = current + "/" + total + "songs";

    //this method is called from worker Thread,so we cannot update UI from here.

    msg.sendToTarget();

Message msg = handler.obtainMessage();

                        msg.arg1 = i;

                        msg.sendToTarget(); 

Message msg=new Message();

    msg.arg1=i;

    handler.sendMessage(msg);