Sort a List by enum where enum is out of order

Question

I have a List of messages. Each message has a type.

public enum MessageType
{
    Foo = 0,
    Bar = 1,
    Boo = 2,
    Doo = 3
}

The enum

Answer 1

An alternative to using IComparer would be to build an ordering dictionary.

var orderMap = new Dictionary() {
    { MessageType.Boo, 0 },
    { MessageType.Bar, 1 },
    { MessageType.Foo, 2 },
    { MessageType.Doo, 3 }
};

var orderedList = messageList.OrderBy(m => orderMap[m.MessageType]);