How do I sort the list of data in reverse date order?

Question

Sample XML:

<AssignmentHistory>
    <PublicTalkInfo>
        <PublicTalkNumber>21</PublicTalkNumber>
        <PublicTalkSpeaker>Name3</PublicTalkSpeaker>
        <PublicTalkCongregation>Place3</PublicTalkCongregation>
    </PublicTalkInfo>
    <PublicTalkInfo>
        <MeetingDate>2023-10-15</MeetingDate>
        <PublicTalkNumber>21</PublicTalkNumber>
        <PublicTalkSpeaker>Name</PublicTalkSpeaker>
        <PublicTalkCongregation>Place</PublicTalkCongregation>
    </PublicTalkInfo>
    <PublicTalkInfo>
        <MeetingDate>2023-11-15</MeetingDate>
        <PublicTalkNumber>21</PublicTalkNumber>
        <PublicTalkSpeaker>Name2 </PublicTalkSpeaker>
        <PublicTalkCongregation>Place</PublicTalkCongregation>
    </PublicTalkInfo>
</AssignmentHistory>

I cut it down for simplification.

public string[] GetHistoryForTalkOutline(string historyDatabase, int talknumber)
{
    List<string> list = new List<string>();
    try
    {
        XDocument doc = XDocument.Load(historyDatabase);
        var ptInfo = doc
                        .Descendants("PublicTalkInfo")
                        .Where(p => p.Element("PublicTalkNumber").Value == talknumber.ToString()).ToList();
        SimpleLog.Log(ptInfo.Count().ToString());
           foreach (var pt in ptInfo)
           {
               var date = pt.Element("MeetingDate");
               var speaker = pt.Element("PublicTalkSpeaker");
               var cong = pt.Element("PublicTalkCongregation");

               if (date != null && speaker != null && cong != null)
               {
                   DateTime objectdate = DateTime.Parse(date.Value);
                   string histitem = objectdate.ToString("d") + ", ";
                   histitem += speaker.Value + " (";
                   histitem += cong.Value + ")";
                   list.Add(histitem);
               }

           }

        return list.ToArray();
    }
    catch (Exception ex)
    {
        SimpleLog.Log(ex);
        return null;
    }
}

I am sure the code can be simplified. But how can I build my final list of strings with the content in descending date order? Note that some entries do not have the fields in.

Answer 1

Instead of storing all the values in a list of strings, you can instead keep them in a format that retains the date value. For example, using a tuple:

List<(DateTime Date, string Value)> list = new List<(DateTime, string)>();

Later when you add to the list, do this:

list.Add((objectdate, histitem));

And to return the values in the order you need, use some simple Linq:

return list
    .OrderByDescending(x => x.Date)
    .Select(x => x.Value)
    .ToArray();