Android 4.4.源码 如何屏蔽Home键

做了一个锁屏app替换系统的app ，但是在应用层是无法屏蔽home键的，找了资料，改了源码，终于解决

代码位置

frameworks\base\policy\src\com\android\internal\policy\impl\PhoneWindowManager.java下的 

定位到名为interceptKeyBeforeDispatching 的函数

从函数名我们可以知道此函数是是在分发按键消息之前进行拦截。

查看对KEYCODE_HOME home键的处理 

        // First we always handle the home key here, so applications
        // can never break it, although if keyguard is on, we do let
        // it handle it, because that gives us the correct 5 second
        // timeout.
        if (keyCode == KeyEvent.KEYCODE_HOME) {


            // If we have released the home key, and didn't do anything else
            // while it was pressed, then it is time to go home!
            if (!down) {
                cancelPreloadRecentApps();


                mHomePressed = false;
                if (mHomeConsumed) {
                    mHomeConsumed = false;
                    return -1;
                }


                if (canceled) {
                    Log.i(TAG, "Ignoring HOME; event canceled.");
                    return -1;
                }


                // If an incoming call is ringing, HOME is totally disabled.
                // (The user is already on the InCallScreen at this point,
                // and his ONLY options are to answer or reject the call.)
                try {
                    ITelephony telephonyService = getTelephonyService();
                    if (telephonyService != null && telephonyService.isRinging()) {
                        Log.i(TAG, "Ignoring HOME; there's a ringing incoming call.");
                        return -1;
                    }
                } catch (RemoteException ex) {
                    Log.w(TAG, "RemoteException from getPhoneInterface()", ex);
                }


                // Delay handling home if a double-tap is possible.
                if (mDoubleTapOnHomeBehavior != DOUBLE_TAP_HOME_NOTHING) {
                    mHandler.removeCallbacks(mHomeDoubleTapTimeoutRunnable); // just in case
                    mHomeDoubleTapPending = true;
                    mHandler.postDelayed(mHomeDoubleTapTimeoutRunnable,
                            ViewConfiguration.getDoubleTapTimeout());
                    return -1;
                }


                // Go home! wdh add 我在此处屏蔽系统的launcher并且return 0，原来是return -1，改为return 0 交由上层app处理home键
                //launchHomeFromHotKey();
                return 0;

上层app处理：重写onKeyDown屏蔽home 和back

/**
* 
* 屏蔽掉返回键
* 
*/
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
// TODO Auto-generated method stub

if(keyCode==KeyEvent.KEYCODE_BACK || keyCode==KeyEvent.KEYCODE_HOME){
return true;
}else {
return super.onKeyDown(keyCode, event);
}
}
          

参考文章：http://www.cnblogs.com/sphere/archive/2014/12/02/4137814.html  

参考文章：http://blog.csdn.net/fulinwsuafcie/article/details/7717408