Sort the generic list and allow two names always to be on top and rest sorted

Question

private List nodes = new List();

there is a label field inside ISilverNodeModel class of type string.

suppose the nodes list is:

Malcolm, Sym, Eric, Sandrea

I want malcolm and Sandrea always on top and rest to be sorted.

I am doing this but it sorts all :

nodes.Sort((node1, node2) => node1.Label. CompareTo( node2.Label));

Answer 1

You can write your own IComparer, and use that implementation in the Sort method.

Your implementation could then determine that malcolm and sandra are always smaller then any other label.

public class MySorter : IComparer<ISilverNodeModelClass>
{
   public int Compare( ISilverNodeModelClass left, ISilverNodeModelClass right )
   {
       if( left.Label.Equals (right.Label) )
           return 0;

       if( left.Label == "malcolm" || left.Label == "sandra" )
          return Int32.MinValue;

       if( right.Label == "malcolm" || right.Label == "sandra" )
           return Int32.MaxValue;

       return Comparer<string>.Default.Compare (left.Label, right.Label);
   }
}

Answer 2

If you're on .NET 3.5, there's a nice way to do it using LINQ:

    List<string> topLabels = new List<string> { "Malcolm", "Sandrea" };
    nodes = nodes
        .OrderByDescending(node => topLabels.Contains(node.Label))
        .ThenBy(node => node.Label)
        .ToList();

Answer 3

                    nodes.Sort((node1, node2) =>
                        {
                            if (node1.Label.Equals(node2.Label))
                            {
                                return 0;
                            }
                            if (node1.Label == "Favorites" || node1.Label == "Recent")
                                {
                                    return Int32.MinValue;
                                }
                            if (node2.Label == "Favorites" || node2.Label == "Recent")
                            {
                                return Int32.MaxValue;
                            }
                            return node1.Label.CompareTo(node2.Label);
                         });