How do I use the IComparable interface?

Question

I need a basic example of how to use the IComparable interface so that I can sort in ascending or descending order and by different fields of the object type I\'m s

Answer 1

This might not be in relation to sorting order, but it is still - I think - an interesting use of IComparable:

public static void MustBeInRange(this T x, T minimum, T maximum, string paramName)
where T : IComparable
{
    bool underMinimum = (x.CompareTo(minimum) < 0);
    bool overMaximum = (x.CompareTo(maximum) > 0);
    if (underMinimum || overMaximum)
    {
        string message = string.Format(
            System.Globalization.CultureInfo.InvariantCulture,
            "Value outside of [{0},{1}] not allowed/expected",
            minimum, maximum
        );
        if (string.IsNullOrEmpty(paramName))
        {
            Exception noInner = null;
            throw new ArgumentOutOfRangeException(message, noInner);
        }
        else
        {
            throw new ArgumentOutOfRangeException(paramName, x, message);
        }
    }
}

public static void MustBeInRange(this T x, T minimum, T maximum)
where T : IComparable { x.MustBeInRange(minimum, maximum, null); }

These simple extension methods allow you to do parameter range checking for any type that implements IComparable like this:

public void SomeMethod(int percentage, string file) {
    percentage.MustBeInRange(0, 100, "percentage");
    file.MustBeInRange("file000", "file999", "file");
    // do something with percentage and file
    // (caller will have gotten ArgumentOutOfRangeExceptions when applicable)
}