屏蔽 Home 按键，至少做到两点：

1） 重写 onAttachedToWindow

2）重写 onKeyDown

@Override  
    public void onAttachedToWindow() {  
        super.onAttachedToWindow();  
        getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD);  
        Log.d("mark", "onAttachedToWindow-- ");  
    }  

@Override  
    public boolean onKeyDown(int keyCode, KeyEvent event) {  
        if (event.getAction() == KeyEvent.ACTION_DOWN) {  
            switch (keyCode) {  
                case KeyEvent.KEYCODE_HOME:  
                    Toast.makeText(this, "home key is pressed", 1).show();  
                    break;  
            }  
        }  
        return super.onKeyDown(keyCode, event);  
    }