Enum and string match

Question

I'm essentially trying to read an xml file. One of the values has a suffix, e.g. "30d". This is meant to mean '30 days'. So I'm trying to convert this to a DateTime.Now.AddDays(30). To read this field in the XML, i decided to use an Enum:

enum DurationType { Min = "m", Hours = "h", Days = "d" }

Now I'm not exactly sure how exactly to approach this efficiently (I'm a little daft when it comes to enums). Should I separate the suffix, in this case "d", out of the string first, then try and match it in the enum using a switch statement?

I guess if you dumb down my question, it'd be: What's the best way to get from 30d, to DateTime.Now.AddDays(30) ?

Answer 1

You could make an ExtensionMethod to parse the string and return the DateTime you want

Something like:

    public static DateTime AddDuration(this DateTime datetime, string str)
    {
        int value = 0;
        int mutiplier = str.EndsWith("d") ? 1440 : str.EndsWith("h") ?  60 : 1;
        if (int.TryParse(str.TrimEnd(new char[]{'m','h','d'}), out value))
        {
            return datetime.AddMinutes(value * mutiplier);
        }
        return datetime;
    }

Usage:

 var date = DateTime.Now.AddDuration("2d");