如何使用泛型参数实例化接口

Question

I have some classes that implement the interface below:

ISearchBase<T>

But I don't know which class will be instantiated, so I let "the user decide", like the example below:

var objectResponse = Activator.CreateInstance(Type.GetType(ResponseNamespace));

The problem is: Each those classes has a return and I'm trying to use like this:

var object = (ISearchBase<objectResponse >)
          Activator.CreateInstance(Type.GetType(Namespace));

But the compiler won't let me do this... What can I do?

The error is:

The type or namespace name 'objectResponse' could not be found.

Answer 1

When you do var object = (ISearchBase<X>)... you must know the type X at compile time. The var keyword is just short-hand for the compiler to infer the type. So, you cannot use a run-time type to resolve for X .

You haven't shown what you what to do with the object after you've created it. It is certainly possible to call a generic method using reflection to allow you to type-safe code, but I can't tell if that will be useful to you or not without seeing more code.