CODEWITHSUNDEEP
c#unity-game-engine
LZG
LZG

Reputation: 63

How to find the type of derived class without multiple "is" statements?

I find a bunch of questions close to this, but not quite answering it, though I'm sure it's on here somewhere.

I'm looking to simply find which derived class I'm dealing with from a base class reference.

I have blocks of code like this

    public void AddMenu(iTarget target, Menu callingMenu)
{
    if (target is Corporation)
        AddMenu(target as Corporation, callingMenu);
    if (target is Company)
        AddMenu(target as Company, callingMenu);
    if (target is Asset)
        AddMenu(target as Asset, callingMenu);
    if (target is Operative)
        AddMenu(target as Operative, callingMenu);
}

And

if (uip.UIPButton is UIPCorporationButton)
        btn = UIPCorporationButton.Create(contents.gameObject, (uip as Corporation));
else if (uip.UIPButton is UIPCompanyButton)
        btn = UIPCompanyButton.Create(contents.gameObject, (uip as Company));
else if (uip.UIPButton is UIPAssetButton)
        btn = UIPAssetButton.Create(contents.gameObject, (uip as Asset));
else if (uip.UIPButton is UIPIndButton)
//so on and so on

And I'd like to use something like this:

public void AddMenu(iTarget target, Menu callingMenu)
{
    AddMenu(BaseClass(target));//or whatever would send iTarget as Corporation, Company, or whatever it's base type is
}

Or something like:

public void DoThing(iTarget target)
{
    switch(target.BaseClass)//or whatever
    {
        case Corporation:
            //stuff
            break;
        case Company:
            //other stuff
            break;
    }
}

Is there a way to just get the derived class and use it as a reference like above?

Upvotes: 0

Views: 92

Answers (2)

jhilden
jhilden

Reputation: 12459

GetType() with an if/else statement will do what you want.

    private abstract class Base1
    {

    }

    private class Extend1 : Base1
    {

    }

        Base1 whatTypeAmI = new Extend1();
        var t = whatTypeAmI.GetType();

        if (t == typeof(Extend1))
            {
                //do work
                Console.WriteLine("hello extend1");
            }
        else {
                Console.WriteLine("I don't know what type I am");
            }
        }

Upvotes: 1

PMF
PMF

Reputation: 17328

Make sure you really need that switch statement first. I don't know how your AddMenu works exactly, but if it takes an ITarget, why do you need the cast at all? Just call it with the base class.

Often, if this "switch on a type" construct is seemingly required, there is a design flaw. A virtual method call is the ordinary way to do this, so consider refactoring your code so you can do 

target.AddMenu(callingMenu);

instead.

Upvotes: 3

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