Passing this by reference (ref this)

Question

Consider the following code snippet( written in a Windows Form Application):

public partial class Form1
{
    ....
    public void Caller()
    {
        Form1 myRef = this;
        Change(ref this)    //--> won't compile because *this* is read-only
        Change(ref myRef);  //--> compiles but doesn't work.
    }
    ....

    public void Change(ref Form1 theRef)
    {
        theRef = new Form1();
        theRef.Text = "I am a new form";
    }
}

Passing this by reference is not allowd. That's ok and sensible. But why passing this indirectly as shown above is not working? As I know if a parameter is passed by reference any assignment in the called method is reflected out to the caller method. Why isn't it working here?

Update to make the question clear

1- I am not struggling to accomplish anything special. I am just trying to test ref.

2- The reason why I misunderstood the ref is that I totally forgot Form1 myRef = this actually copies the address of underlying Form1 object to myRef; so myRef variable has nothing to do with this except that both of them points to the same object.

Answer 1

It works as it should. The problem is that this is not the same as what you are expecting.

Form1 myRef = this;
var b1 = object.ReferenceEquals(myRef, this); // true
Change(ref myRef);
var b2 = object.ReferenceEquals(myRef, this); // false

So the value of myRef changes. That the change does not propagate to this should be expected; after making the assignment myRef and this are totally separate variables. C# does not have "ref variables", so it couldn't be any other way (even if it had, reassigning this in this manner would never be allowed).