activity onkeydown 单任务 屏幕改变方向不调用oncreate()方法

//按back建该activity还在  按home键启动该activity

 @Override
    public boolean onKeyDown(int keyCode, KeyEvent event)
    {
      if(keyCode==KeyEvent.KEYCODE_BACK)
         {
             return true;
         }
     //下面的代码不起作用，这样屏蔽不了home键
      if(keyCode==KeyEvent.KEYCODE_HOME)
      {
       startActivity(new Intent(this, HomePageActivity.class));
       return true;
      }

        return super.onKeyDown(keyCode, event);
    }

//单任务 屏幕改变方向不调用oncreate()方法

<activity
android:name="com.example.mxhome.AppCategoryActivity"
android:label="@string/title_activity_app_category"
android:launchMode="singleInstance"
android:screenOrientation="portrait"
android:configChanges="keyboardHidden|orientation">
</activity>