private async Task JoinMeetingAsync() { uint mId; if (!uint.TryParse(MeetingId, out mId)) { HasErrorMsg("-1", Messages.WarningInvalidMeetingNo); return; } int meetingId = (int)mId; if (meetingId == 0) { HasErrorMsg("-1", Messages.WarningInvalidMeetingNo); return; } AsynCallResult result = await _sdkService.QueryMeetingExist(meetingId); if (result.m_rc == 6) { result.m_message = Messages.WarningMeetingNoDoesNotExist; } if (HasErrorMsg(result.m_rc.ToString(), result.m_message)) { return; } _sdkService.SetMeetingId(meetingId); await GotoMeetingViewAsync(); }