屏蔽返回键的代码:public boolean onKeyDown(int keyCode,KeyEvent event){        switch(keyCode){        case KeyEvent.KEYCODE_HOME:return true;case KeyEvent.KEYCODE_BACK:return true;case KeyEvent.KEYCODE_CALL:return true;case KeyEvent.KEYCODE_SYM: return true;case KeyEvent.KEYCODE_VOLUME_DOWN: return true;case KeyEvent.KEYCODE_VOLUME_UP: return true;case KeyEvent.KEYCODE_STAR: return true;}return super.onKeyDown(keyCode, event);} 屏蔽home键的代码:public void onAttachedToWindow() {        this.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD);super.onAttachedToWindow();}