Handle the Closed event in Form1 by adding it to the Form2 instance you create just before you call Show on it.
When the Form2instance closes, the event will be raised, and you will have Form1 in
Me
as usual, and Form2 is passed to you as the
sender
parameter.
You can then use a property or method in Form2 to access the information Form1 needs:
The form that creates an instance of another:
MyForm mf = new MyForm();
mf.Show();
Is the "parent", the other form is the "child".
(This doesn't imply any formal MDI relationship)
Transferring information between two forms, Part 2: Child to Parent[
^] The code is in C#, but it's pretty simple and obvious.