Create instance of generic class with dynamic generic type parameter

Question

I need to create instance of a generic class like this:

 Type T = Type.GetType(className).GetMethod(functionName).ReturnType;
 var comparer = new MyComparer&         


        

Answer 1

Looks like you're almost there:

// t is a variable, so make it lowercase. This is where some of the confusion comes from
Type t = Type.GetType(className).GetMethod(functionName).ReturnType;
Type myGeneric = typeof(IEqualityComparer<>);

// You need to provide the generic type to make it generic with
// You want IEqualityComparer, so:
Type constructedClass = myGeneric.MakeGenericType(t); 

// Now create the object
object created = Activator.CreateInstance(constructedClass);

// This is tricky without more context...
// You could try this, but to tell you more I would need to know where you use
// the comparer instance. Are you using it in a LINQ query, or in a Sort()?
// If so just cast it to a IEqualityComparer, and
// make YourType whaterver you need it to be in the list or the query...
var comparer = (IEqualityComparer