C#: Create variable with typename in runtime (rtti?)

Question

I need to create some variable with some predefined type which stored in other variable value. In pseudo code it looks like:

string typeName = "int";
object refToObj;
create data refToObj type typename.

write refToObj.getSize();

This pseudo-code must create var refToObj with type int, and then return 4 in output (write instruction.. ).

How can I do this in C#?

Answer 1

Something like the following?

Type t = Type.GetType("System.Int32");

Console.WriteLine("Sizeof: " + System.Runtime.InteropServices.Marshal.SizeOf(y));   
Console.WriteLine("Type: " + t);

var x = Activator.CreateInstance(t);

Console.WriteLine("Value: " + x);

Will output:

Sizeof: 4
Type: System.Int32
Value: 0

NOTE: int is an alias to the underlying System type which would differ on 32/64-bit operating systems. For Activator.CreateInstance you need to appropriate system types for it to succeed although you could have some form of Dictionary mapping.