Can I use inheritance with an extension method?

Question

I have the following:

public static class CityStatusExt
{
    public static string D2(this CityStatus key)
    {
        return ((int) key).ToString(\"D2\");         


        

Answer 1

You can make the method generic. C# will infer the type:

public static class Extension 
{ 
    public static string D2 (this T key) 
    { 
        return ((int)(object) key).ToString("D2"); 
    } 
}