Clever Geek Handbook

Sort and group the list of objects by several properties

I have a complex sort / grouping that needs to be done on a list of objects.

Objects have three properties: Event name Start End

I am assigned the event name "EventName" and the start / end time for the specified event and populated with a List.

Now comes the tricky part.

Requirements: - the same EventName can have several records with different start and end times - events must be sorted by start time, with the earliest events first - events, if they have the same start time, then must be sorted by the shortest and longest times execution. - events are then grouped, so all events with the same name are listed in ascending order under the event name. - Events with different names but the same total early start time are sorted alphabetically.

For example:

List (0):

EventName: Test 2 Start: 10am End: 3pm

List (1):

EventName: Test 2 Start: 10am End: 11am

List (2):

EventName: Test 1 Start: 12pm End: 1pm

List (3):

EventName: Test 2 Start: 2pm End: 3pm

So when all is said and done, the list should be sorted like:

List (0):

EventName: Test 2 Start: 10am End: 11am

List (1):

EventName: Test 2 Start: 10am End: 3pm

List (2):

EventName: Test 2 Start: 2pm End: 3pm

List (3):

EventName: Test 1 Start: 12pm End: 1pm

I'm really not sure how to do this. I have this a lot that doesn't work:

theList.OrderBy(o => o.Start).ThenBy(o => o.End).ThenBy(o => o.EventName);

Any help would be appreciated.

EDIT To make it easier, let's say the time is converted to 24 hour time and stored as ints, how can I easily do this.

+3


source to share


3 answers


I believe I have it!

I just had to do some little tweaks to what I already had.

Here's the code that still works as I need it:



theList.GroupBy(o => o.EventName).Select(s => s.OrderBy(a => a.Start).ThenBy(a => a.End)).SelectMany(sm => sm).ToList();

In cases where all other offers fell, the EventNames grouping was grouped when sorted by start time.

_

+2


source


Solution without Linq:

theList.Sort(delegate(Event p1, Event p2)
             {
                   var byStart = p1.Start.CompareTo(p2.Start);
                   var byEnd = p1.End.CompareTo(p2.End);
                   var byEventName = p1.EventName.CompareTo(p2.EventName);
                   return byStart == 0 ? byEnd == 0 ? byEventName : byEnd : byStart;
             });


Solution adapted from Sorting list by code, then by name . Unverified. Especially the return statement may need manipulation. Replace the event with whatever you are using as the List object.

0


source


You need to store Start

and End

in temporary variables without am and pm, and then perform a sort operation on these numbers Suppose that a class name that has these three properties Event

, then here is the linq operator

list.Select(s => new
 {
    EventName = s.EventName,
    Start = s.Start,
    End = s.End,
    // getting number without am/pm and where it is pm adding 12
    NumberStart = s.Start.EndsWith("pm") ?
                    12 + Convert.ToInt32(s.Start.Trim('m').TrimEnd('p')) : 
                         Convert.ToInt32(s.Start.Trim('m').TrimEnd('a')),
    NumberEnd = s.End.EndsWith("pm") ?
                    12 + Convert.ToInt32(s.End.Trim('m').TrimEnd('p')) :
                         Convert.ToInt32(s.End.Trim('m').TrimEnd('a'))
 }).OrderBy(s => s.NumberStart)
   .ThenBy(s => s.NumberEnd - s.NumberStart)
   .ThenBy(s => s.EventName)
   .Select(s => new Event { EventName = s.EventName, Start = s.Start, End = s.End });

Edit

try changing the sequence OrderBy

to

.OrderBy(s => s.EventName)
   .ThenBy(s => s.NumberStart)
   .ThenBy(s => s.NumberEnd - s.NumberStart)
0


source






More articles:


All Articles