app启动时禁用返回键以防闪屏处理

public boolean onKeyDown(int keyCode, KeyEvent event) {

                   // TODO Auto-generated method stub

                   if(keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0){

                            System.out.println("返回键执行了！！！");

                   }

                   return true;

}