Using reflection to create an instance

Question

To create an instance of a class we can do that :

Person p = new Person();

But, I want to pass the name of class dynamicaly with a string like that :

String name = "Human.Person"
name n = new name();

I know this is wrong but I saw that I can use reflection but I didn't understand how can I use it for my case.

Also I've removed the visual studio tag. Please only include relevant tags. — David L, Mar 09 '17 at 21:25

score 2 · Accepted Answer · answered Mar 09 '17 at 21:25

2

You can use Activator.CreateInstance for this scenario.

object person = Activator.CreateInstance(Type.GetType("Human.Person"));

or most commonly using a base class or interface:

IPerson person = (IPerson)Activator.CreateInstance(Type.GetType("Human.Person"));

answered Mar 09 '17 at 21:25

EventHorizon

And if I want to open a form like : `Class c = new Class(); c.Show();` ? – Med Mar 09 '17 at 22:55
Your class will inherit from Form, so you can use Form c = (Form)Activator.CreateInstance( ... ) – EventHorizon Mar 09 '17 at 23:00
Like that : `Form c = (Form)Activator.CreateInstance(Type.GetType("Human.Person");` ? I have a ArgumentNullException – Med Mar 09 '17 at 23:06
My Bad, an error in my class name. Now it works thx – Med Mar 10 '17 at 00:14

Liu · Answer 2 · 2017-03-09T21:40:39.287

1

  Type t = Type.GetType(name); 
  Human.Person p = Activator.CreateInstance(t) as Human.Person;

Updated: Thanks @Dag If Human.person is in another assembly

Type t = a.GetType(name, "assemblyName"); 
Human.Person p = Activator.CreateInstance(t) as Human.Person;

edited Mar 09 '17 at 21:40

answered Mar 09 '17 at 21:30

Liu

You don't need to load it, just add the assembly name to the type name like this "Human.Person,something" – EventHorizon Mar 09 '17 at 21:36
You are right. Thanks – Liu Mar 09 '17 at 21:39

2 Answers2