Android 开启子线程简单流程

一直都在用，却没有积累下来，简单的东西还是记一下吧！
1、

    private class DownLoadThread extends Thread {        @Override        public void run() {            Message message = new Message();                    message.what = 0;                    handler.sendMessage(message);        }    }

2、

 private final Handler handler = new Handler() {        @Override        public void handleMessage(Message msg) {            switch (msg.what) {                case 0:                //处理任务，如更新UI                    break;                case 1:                break;                default:                    break;            }        }    };

3、

 Message message = new Message(); message.what = 0; handler.sendMessage(message);

4、

  new DownLoadThread().start();