Case-INsensitive Dictionary with string key-type in C#

Question

If I have a Dictionary is it possible to make methods like ContainsKey case-insensitive?

This seemed related, but I didn\

Answer 1

I just ran into the same kind of trouble where I needed a caseINsensitive dictionary in a ASP.NET Core controller.

I wrote an extension method which does the trick. Maybe this can be helpful for others as well...

public static IDictionary ConvertToCaseInSensitive(this IDictionary dictionary)
{
    var resultDictionary = new Dictionary(StringComparer.InvariantCultureIgnoreCase);
    foreach (var (key, value) in dictionary)
    {
        resultDictionary.Add(key, value);
    }

    dictionary = resultDictionary;
    return dictionary;
}

To use the extension method:

myDictionary.ConvertToCaseInSensitive();

Then get a value from the dictionary with:

myDictionary.ContainsKey("TheKeyWhichIsNotCaseSensitiveAnymore!");