Question

If I have this code:

Label label1 = new Label();  
Form1.Controls.Add(label1);  
Label label2 = label1;

What’s really on From1? Is it label1? Or is it the object label1 points to?

In other words if I then have this:

Form1.Controls.Remove(label1);

have I effectively removed the label? Or is label2 keeping it on the form?

I guess I’m wondering, is it the pointer that’s on the Form, or is it the object the pointer points to?

Answer 1

Controls.Add() adds a reference to whatever Control you pass to it. label2 = label1 just creates another reference to label1. Controls.Remove() doesn’t delete the object, it just removes it from its list of controls.

So, in your example, after you call Controls.Remove():

• label1 would still “exist” (i.e. it will not be garbage collected).
• label2 would reference label1.
• The label would not still be part of the form because the form’s list of controls no longer contains a reference to the label.