当屏幕多久没有点击的时候，进行某种操作就是所谓的锁屏功能。

onCreate:

public void addRunnable() {        handler.postDelayed(runnable, Constant.WAIT_TIME);    }

监听触摸事件：

@Override    public boolean dispatchTouchEvent(MotionEvent ev) {        // TODO Auto-generated method stub        handler.removeCallbacks(runnable);        addRunnable();        return super.dispatchTouchEvent(ev);    }    Runnable runnable = new Runnable() {        @Override        public void run() {            // TODO Auto-generated method stub            // 锁屏的操作                        long time2 = System.currentTimeMillis() - time1;            LogUtil.i(TAG, "time2= " + time2);                        doLock();        }    };

onDestroy:

handler.removeCallbacks(runnable);