继承TabActivity后不执行onBackPressed()里的方法

// 用下面这个函数拦截子Activity的返回操作
        @Override
        public boolean dispatchKeyEvent(KeyEvent event) {
                 if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
                                 //do something
                 }
                 return super.dispatchKeyEvent(event);
        }