How to group properties in c#?

I am not sure if I phrased the question correctly, but this is what I am trying to do.

I am writing test framework for a program that takes a set of args. I am developing a public class to deal with operations regarding these args. So that user can use like,

Load(SampleProgram.CommandArgs args)
{}

public class CommandArgs
{
    public string Arg1
    { 
        get; set;
    }

    public string Arg2
    { 
        get; set;
    }

    public string Arg3
    { 
        get; set;
    }

    public string Parsedvalue
    { 
        get; set;
    }

    //......and so on..
}

My problem is that in these args, Arg2 and Arg3 belong a type and user might need to change the开发者_JAVA百科m later, even though the rest of args might not changes. So I moved the arg2 and arg3 into a seperate class and I want CommandArgs class to reuse it. How do I do this?

I tried this

public class CommandArgs
{
    private GroupedCommandArgs grpargs = null;

    public string Arg1
    { 
        get; set;
    }

    //......and so on..
}

//In constructor..
grpargs = new GroupedCommandArgs(arg2, arg3);

This works so that if user wants to change arg2, he or she can write,

CommandArgs.GroupedCommandArgs.arg2 = "something";

But, what I also need is that each time arg2 or arg3 changes, I need to update some of the properties like Parsedvalue.

How do I do this? My code is in c#.

Thanks

---

Use inheritance. Include the common arguments in the base CommandArgs class and for cases with exctra properties create subclasses like AdditionalCommandArgs.

class CommandArgs
{
    public string Arg1 { get; set; }

    public virtual string ParsedValue
    {
        get
        {
            return "Arg1: " + Arg1;
        }
    }
}

class AdditionalCommandArgs : CommandArgs
{
    public string Arg2 { get; set; }

    public string Arg3 { get; set; }

    public override string ParsedValue
    {
        get
        {
            return base.ParsedValue + "\r\n" +
                   "Arg2: " + Arg2 + "\r\n" +
                   "Arg3: " + Arg3;
        }
    }
}

---

If the main thing you want is to allow your code to intercept the change in value of Arg2, Arg3, etc., and then fire off a change to a different property, you would probably want to implement INotifyPropertyChanged

Check out the example here: http://msdn.microsoft.com/en-us/library/system.componentmodel.inotifypropertychanged.propertychanged.aspx

And then, in your own custom NotifyPropertyChanged method, make sure to update Parsedvalue as you wish.