Sorting list in C#

Question

I have a list of custom type. And the custom type is

public class PossibleMatch
    {
        public PossibleMatch()
        {
            StoreIds = new List<long>();
            OrderLineIds = new List<long>();
        }
        public IList<long> StoreIds { get; set; }
        public IList<long> OrderLineIds { get; set; }
    }

I have to sort the list in such a way item with less number of stores and more number of order lines should be at top.

Thanks in advance.

Answer 1

LINQ has just the methods for this.

Try the following to order by matches with the fewest StoreIds first and then to sub order by matches with the most OrderLineIds:

 var possibleMatches = new List<PossibleMatch>();
 var ordered = possibleMatches.OrderBy(pm => pm.StoreIds.Count).ThenByDesc(pm => pm.OrderLineIds.Count);

Or to order by matches with the most OrderLineIds first and then to sub order by matches with the fewest StoreIds:

var ordered = possibleMatches.OrderByDesc(pm => pm.OrderLineIds.Count).ThenBy(pm => pm.StoreIds.Count);

Answer 2

Build Custom Comparer:

public class PossibleMatchComparer: IComparer<PossibleMatch>
{
    public int Compare(PossibleMatch x, PossibleMatch y)
    {
        if (x.StoreIds.Count < y.StoreIds.Count) return -1;
        if (x.StoreIds.Count > y.StoreIds.Count) return 1;

        return y.OrderLineIds.Count - x.OrderLineIds.Count;
    }
}

So you can use:

list.Sort(new PossibleMatchComparer());