Generics and objects conversion in C#

Question

I have a class which is handling objects same way. It's like:

class Handler<T>{
    private T _obj;
    public T obj{
        get{
            ...//do sth
            return _obj;
        }
        set{
            ...//do sth
            _obj = value;
        }
    }
    ... // some other properties, no T anymore
}

There are large amount of code working on Handler objects, ignoring type. I mean, type T is not for them, there are setting other fields. There are containers with Handler<> and so on.

At the end I need to return Handler with correct type.

I wanted to use Handler<object>, but there is no way I know to convert it to Handler<SomeClass>.

How can I handle situtations like this?

Maybe this is helpful: http://stackoverflow.com/questions/4092393/value-of-type-t-cannot-be-converted-to — Tim Schmelter, Dec 07 '12 at 12:20

Dennis · Accepted Answer · 2012-12-07T12:53:57.387

3

Why don't you make a base class for Handler<T>, which will contain all non-generic code?

class HandlerBase
{
   // some other properties
}

class Handler<T> : HandlerBase
{
    public T obj { ... }
}

If your "large amount of code" ignores T, than let it work with HandlerBase.

edited Dec 07 '12 at 12:53

answered Dec 07 '12 at 12:36

Dennis

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score 0 · Answer 2 · answered Dec 07 '12 at 12:45

0

You can try with an IHandler interface.

IHandler<SomeClass> h1 = new Handler<SomeClass>();
IHandler<Object> h2 = h1;

This will work !
More info on Covariance on MSDN

answered Dec 07 '12 at 12:45

knaki02

183
11

Generics and objects conversion in C#

2 Answers2