Why I call the GetMeetingUIWnd interface and return the values firstViewHandle and secondViewHandle always null

I’m using zoom_sdk_c_sharp_wrap(v5.0.24433.0616), and the code snippets:

switch (status)
        {
            case MeetingStatus.MEETING_STATUS_ENDED:
            case MeetingStatus.MEETING_STATUS_FAILED:
                {
                    Show();
                }
                break;
            case MeetingStatus.MEETING_STATUS_INMEETING:
                IMeetingUIControllerDotNetWrap meetingUI = CZoomSDKeDotNetWrap.Instance.GetMeetingServiceWrap().GetUIController();
                ValueType firstViewHandle = null;
                ValueType secondViewHandle = null;
                SDKError resultSDKError= meetingUI.GetMeetingUIWnd(ref firstViewHandle, ref secondViewHandle);

                break;
            default://todo
                break;
        }

resultSDKError is success ,but firstViewHandle ,secondViewHandle always null~ why ?

Similar to this problem, have you solved it?