Question

I’m trying to figure out how to create a sorted dictionary where the key is sorted in a non-alphabetical manner. Is there a way I can define the way I want it to sort?

For example, the keys might be in order like the following:

AAA1X
AAB1Y
AAC1Y
AAA2X
AAB2Y
AAC2X

Although the first three letters are alphabetical, if I sort as is it will lump them in the wrong order (due to the number). Also note, that there is either a X or Y at the end. In the code, there will only ever be an X or a Y.

Even if I can write an enumeration for the ordering of all possible combinations I’d be willing to do that as well, but I’m not sure how I can use the sorted dictionary and an enumeration…

I know this is a bit vague, but any help would be much appreciated!

Cheers!

Answer 1

One of the constructors for SortedDictionary<TKey, TValue> takes an IComparer<TKey>, where you can specify a custom comparer class that the dictionary will use for sorting.

public class CustomComparer : IComparer<string>
{
    public int Compare(string x, string y)
    {
        // do your own comparison however you like; return a negative value
        // to indicate that x < y, a positive value to indicate that x > y,
        // or 0 to indicate that they are equal.
    }
}

...

SortedDictionary<string, object> dict = 
              new SortedDictionary<string, object>(new CustomComparer());