Type as a variable

John

Does anyone know how to make this type of code work?
Type t = typeof(int); // can also be a user designed type
var x= new t(); // won't work!
Same sort of issue: given a MethodInfo, "mi" invoked on an object, the resultant is of type object and must be cast. This works:
int n = (int) mi.Invoke(someobject, null); n has correct value
This does not work:
Type t = typeof(int);
var n = (t) mi.Invoke(someobject, null);
Any idea on how to do this? It works in Delphi but I cannot port the code to C#!
Thanks!

4 Replies

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theLizard16y ago
Have you tried

if(t.GetType() is (or == ) myObjectType)
myObjectType = new t();

Just an idea!!
Sam Hobbs16y ago
I think the code you are showing as an explanation of what you need does not work, but since it is provided as the explanation, I don't understand.
John16y ago
I wasn't as clear as I should have been. The example I gave works because I was using a known type, an int. In my real issue I am reflecting on a class and may find data of a wide variety of types. Each type is saved in a list so the code will need to run more like:

Type t = list[i].Type;
MetodInfo mi = list[i].GetMethod;
var some_value = (t) mi.Invoke(some_object, null);
or, in another instance, something like
Type t = list[i].Type;
if (t is OneOfMyCollectorClasses)
{ t mycollection = new t();}
I have looked at the Activator class, but it too only returns an object. How do I cast this object up to the type it is?
john
Sam Hobbs16y ago
Why do you need to use a var instead of an explicit type as you show in the first example? I don't understand why you need to do that so I am not sure what you need to do. Can you just do:

var n = mi.Invoke(someobject, null);

If I knew why that does not work for you then perhaps I could help. Note that if you do that from a function and then return that var item, that won't work as you expect it to.

It will be much better to use the explicit type as in the first example you show.