Question

Is it possible to use LINQ OrderBy like so:

.OrderBy(x=>(x.SourceID == 3), (x.SourceID == 2), (x=>x.SourceID == 4), (x.SourceID == 1)).ToList();

So it’ll order them by 3, 2, 4, 1 ?

Answer 1

Taking Joachim Isaksson’s answer above, this could be wrapped in an extension method:

public static class ListExtensions
{
    public static List<Source> SortByCustomOrder(this List<Source> list, List<int> sortOrder)
    {
        return list.OrderBy(x => sortOrder.IndexOf(x.SourceId)).ToList();
    }
}

replacing Source with your Class and x.SourceId with your property

Usage:

// the sort order
var sortOrder = new List<int> { 3, 2, 4, 1, 6, 5 };
var results = sources.SortByCustomOrder(sortOrder);