Question

At compile time, I don’t know what exact type I will pass to a method, but I am sure that this type will contain some property. How can I pass a Type to a function to perform casting in the function? I would like to get something like that:

foo (classType cl)
{
    int x = ((cl)SomeClass).Id.Value;
}

Answer 1

The other answer won’t work when using .id because your T type isn’t constrained. The class has no idea that any T could implement a field/property called id

Imagine you used instead

foo <int>()

T would be int and int doesn’t have an id field/property

You can constrain though

foo <T>()
  where T : ClassTypeThatImplementsId
{
  int x = ((T)SomeClass).Value;
}

Though this means that T can only be of that particular type. Is there a base class that has ID that you can use instead? I don’t know if this is the solution you want though…

Edit:

In response to your post:

foo <T>()
  where T : BaseClass
{
  int x = ((T)SomeClass).Value;
}

Should work assuming BaseClass implements ‘Value’ (and assuming SomeClass comes from somewhere as there appears to be no reference to it in the method!)