android屏蔽返回键和home键

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();
}