How to use pointers in C#?

In C# itself, there are no pointers. (They are under cover and you don't need to worry about them.) If you are not working with P/Invoke, or calling unmanaged code or doing some kind of magic, you don't need them.

If you realy want to work with pointers, you have to switch to unsafe mode (a block statement modifier, method modifier or global compiler option).

But in your case, it seems to me that you don't need pointers. Which you need is a reference - variable which points to an object, not to a memory address. With exception of value types (Int32, struct) every variable is reference.

The ref modifier of a parameter allows you to assign different object to the passed parameter, or modifie the place where the reference point outside the method. Look at the example:

class Model
{
public int i = 0;
}

public void Foo(Model m)
{
m.i = 1;
}

public void Bar(ref Model m)
{
m.i = 2;
m = new Model();
}

Model m = new Model();
Foo(m);
// now m.i is 1
Bar(m)
// now m.i is 0, because it points to new instance created in Bar
// the original instance of Model is now subject to GC

Was this what you were asking about? ;-)

public unsafe void FunctionName(SomeObject* obj) {
obj->Foo();
}