Question

I have a List<Event> and an Event has a Date property. I’m currently binding this list to an asp:repeater which is fine and results in a list of event titles like this:

event 1
event 2
event 3
event 4
event 5

However, now I wish to add some kind of separator to my list between events occurring on different days so that my list looks like:

Tuesday, May 10, 2011
event 1
event 2
Wednesday, May 11, 2011
event 3
Thursday, May 12, 2011
event 4
event 5

Can anyone recommend a good way to do this. I’m happy to manipulate my list server-side or to bind my list and then add the separators client-side with jQuery. Any suggestions?

Answer 1

You can group by date server side using Linq’s GroupBy

class Event
{
    public DateTime EventDate;
    public string EventName;
}

List<Event> events = GetEvents();

var grouped = events.GroupBy(e => e.EventDate.Date).OrderBy(g => g.Key);

foreach (var grouping in grouped)
{
    Console.WriteLine(grouping.Key); // <-- this is the date

    foreach (Event e in grouping) // <-- this is the list of events
    {
        Console.WriteLine(e.EventName); 
    }
}

GroupBy returns IEnumerable<IGrouping<TKey, TSource>>, so in this case you are returning IEnumerable<IGrouping<DateTime, Event>>