CODEWITHSUNDEEP
c#generics
Santhosh
Santhosh

Reputation: 20406

how to create instance for a generic type in c#

I need to create an parameterless instance for a Generic Class in C#.

How to do this.

Upvotes: 3

Views: 5927

Answers (1)

Marc Gravell
Marc Gravell

Reputation: 1062510

You could add the : new() constraint:

void Foo<T>() where T : class, new() {
    T newT = new T();
    // do something shiny with newT
}

If you don't have the constraint, then Activator.CreateInstance<T> may help (minus the compile-time checking):

void Foo<T>() {
    T newT = Activator.CreateInstance<T>();
    // do something shiny with newT
}

If you mean you the type itself, then probably something like:

Type itemType = typeof(int);
IList list = (IList)Activator.CreateInstance(
         typeof(List<>).MakeGenericType(itemType));

Upvotes: 21

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