Create intance of any C# class by generic way

Question

i want to create instance of any class by generic way. is that possible?i know ,this is madly but this is only a question waits the its answer.

i tried this but doesnt work.

public class blabla {
 public void bla();
}

public class Foo<T>
{

        Dictionary<string, Func<object>> factory;

        public Foo()
        {
          factory = new Dictionary<string, Func<object>>();
        }

        public WrapMe(string key)
        {

            factory.Add(key, () => new T());

        }
 }

 Foo<blabla> foo = new Foo<blabla>();
 foo.Wrapme("myBlabla");
 var instance = foo.factory["myBlabla"];
 instance.Bla();

Answer 1

There are two ways to solve this:

Variant 1: Add where T : new() to your class definition:

public class Foo<T> where T : new()
{
    ...
}

For further details, see the description of the new() constraint.

---

Variant 2: Pass the lambda () => new T() as a parameter to your constructor, store it in a Func<T> field and use it in WrapMe.

For further details, see this blog post

Answer 2

You only need a method:

static T InstantiateInstance<T>() where T : new()
{
    return new T();
}

Answer 3

You need to use the new constraint when declaring Foo. This only works for types with a constructor with no arguments - which is fine in your case.

Answer 4

You can use Activator.CreateInstance<T>().

Answer 5

Use an Inversion of Control container, like Castle Windsor.