Sorting a SortedDictionary based on value, not key

Question

I have a SortedDictionary, the key is a int value and the matching value to each key is a class object. The class contains a int and a two datetime variable.

I need to sort my SortedDictionary based on the InTime datetime in my class. So that when I do a foreach to loop through my SortedDictionary I will have them sorted based on datetime.

Is this possible? How can I achieve it?

enter code here
 class Busdetail
    {
        public int BusNo { get; set; }
        public DateTime InTime { get; set; }
        public DateTime OutTime { get; set; }
    }

possible duplicate of http://stackoverflow.com/questions/289/how-do-you-sort-a-c-dictionary-by-value — WildCrustacean, Aug 05 '10 at 17:20
possible duplicate of [.NET SortedDictionary But Sorted By Values](http://stackoverflow.com/questions/2619051/net-sorteddictionary-but-sorted-by-values) — nawfal, May 22 '14 at 05:28

score 12 · Answer 1 · answered Aug 05 '10 at 17:39

Sorted Dictionary will always sort on the key, so there is no way to re-arrange it's data so they are sorted on anything other that the key. What you can do is get the data into another structure (some kind of IOrderedEnumerable) where they can be sorted on things other that the key.

If you want to discard the keys and just get the values then

var sortedValues = dictionary.Values.OrderBy(busDetail => busDetail.InTime);

will work, and the type of sortedValues will be IOrderedEnumerable<BusDetail>. If you still need to keep both the keys and values, you could do:

var sortedElements = dictionary.OrderBy(kvp => kvp.Value.InTime);

which will return a IOrderedEnumerable<KeyValuePair<int, BusDetail>>. You can that foreach on any of these two collections, or you could bind them to a grid's datasource.

To sort the dictionary each time you enter or remove from it? — shinzou, Apr 09 '17 at 19:32

score 3 · Answer 2 · answered Aug 22 '13 at 19:33

SortedDictionary can't be sorted by value, though you can extract a sorted list of values, as the other answers point out.

What you want to do is use a list of keyvaluepairs instead, then sort that, like so:

List<KeyValuePair<int, BusDetail>> busses = GetMyListOfBusses();
busses.Sort((first, next) => { 
     return first.Value.InTime.CompareTo(next.Value.Intime); 
});

At that point, your keyvaluepair list of busses will be sorted by InTime

score 1 · Answer 3 · answered Feb 06 '17 at 19:03

1

I think you can use SortedSet and Tuple of your key and value, like: SortedSet> ((a,b)=>(a.Item2.CompareTo(b.Item2));

answered Feb 06 '17 at 19:03

user3413823

11
1

1

This will break the set property of the sorted set. This causes the set to accept the same value twice (key = x, value = 10) (key = x, value = 5). It breaks the set in the sense that he may want the dictionary property of only having unique keys. – Lucas Montenegro Carvalhaes Jul 15 '20 at 19:50

score 1 · Answer 4 · answered Jan 17 '18 at 17:57

1

You could use a Linq query.

var D = new SortedDictionary<int, string>();
var qD = from kvp in D
         orderby kvp.Value
         select kvp
;

answered Jan 17 '18 at 17:57

Lehonti

133
8

Sorting a SortedDictionary based on value, not key

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