Question

I would like to include several additional properties that extend the basic functionality, for example public bool Success { get; set; } or override ErrorCode to return an int instead. Is something like that possible?

Answer 1

Nope you can’t extend the built-in types, but you can override the default error handling to use your own error handling.

But as an int is just a stricter string, I would personally leave it as-is and just use a helper extension method, e.g:

public static class ResponseStatusExtensions {
    public int? ErrorNumber(this ResponseStatus status) {
        int errNum;
        return int.TryParse(status.ErrorCode, out errNum) ? errNum : (int?)null;
    }
}

Then you can use it like:

if (response.ResponseStatus.ErrorNumber() == 100) { ... }