AppointmentItem agendaMeeting = (AppointmentItem)new Microsoft.Office.Interop.Outlook.ApplicationClass().CreateItem(Microsoft.Office.Interop.Outlook.OlItemType.olAppointmentItem);

agendaMeeting.MeetingStatus = OlMeetingStatus.olMeeting;

agendaMeeting.Location = localtion[];

agendaMeeting.Subject = string.Format("{0} {1:yyyy-MM-dd} {2}", txtSubject.Text, dtpStart.Value, agendaMeeting.Location);

agendaMeeting.Body = txtBody.Text;

agendaMeeting.Start = dtpStart.Value;

agendaMeeting.End = dtpEnd.Value;

Recipient recipient = agendaMeeting.Recipients.Add(localtion[]);

recipient.Type = (int)OlMeetingRecipientType.olRequired;

System.Text.RegularExpressions.Regex regex = new System.Text.RegularExpressions.Regex("([A-Za-z0-9_-]+(\\.\\w+)*@(\\w+\\.)+\\w{2,5})", System.Text.RegularExpressions.RegexOptions.IgnoreCase);

var match = regex.Matches(txtRecipients.Text);

foreach (System.Text.RegularExpressions.Match item2 in match)

{

    agendaMeeting.Recipients.Add(item2.Value);

}

((_AppointmentItem)agendaMeeting).Send();

Thread.Sleep();

AppointmentItem appt = (new Microsoft.Office.Interop.Outlook.ApplicationClass()).Session

    .GetDefaultFolder(OlDefaultFolders.olFolderCalendar).Items.Find(string.Format("[Subject]='{0}'", agendaMeeting.Subject)) as AppointmentItem;

if (appt != null)

{

    bool isDeclined = false;

    foreach (Recipient recip in appt.Recipients)

    {

        if (recip.Name.Contains("会议室") && recip.MeetingResponseStatus == OlResponseStatus.olResponseDeclined)

        {

            //预定失败

            isDeclined = true;

            break;

        }

    }

    if (!isDeclined)

    {

        break;

    }

}