Form Instantiation

[wavering]

I am 5 months into converting my project from VB6 to vb.net (don't ask) and have just re-organised to do it properly. To be specific, I am treating forms as a class rather than as in VB6 where you just take them for granted.

I declare them, just like you would a string or an integer. So, what would you expect to happen in the following piece of code (be honest). Then see the screenshot below

Module Module1

Friend MyForm1 As New Form1 

Sub Main()
  MsgBox(MyForm1.Name)
End Sub

End Module

So, why does that happen. Well, there is an excellent article here on auto instantiation:

http://visualbasic.about.com/od/usin.../a/NewForm.htm

but it does not really answer my question ...

As for why Microsoft added "auto instantiation" my guess is that it is a bit of kludge to cater for the great unwashed ie VB6 programmers and they are rather embarrassed about it. The result, as far as I can see, is a mess. If you use auto instantiation you get some ambiguities and if you do it explicitly you also get some ambiguities ... but maybe I am totally wrong! I await elucidation from my betters ...

.

[DataMiser]

Well as I see it you are making a copy of Form1. I would not expect the name to change, it is assigned in the original Form1 properties.

[wavering]

Well as I see it you are making a copy of Form1. I would not expect the name to change, it is assigned in the original Form1 properties.

LOL! I have wracked my brains trying work out what was happening but your explanation was staring me in the face and I could not see it.

Apologies for wasting people's time ... I will go and find a hole to hide in ...

But the article on "auto instantiation" (no connection to me) is well worth reading as this is important but obscure
.

[wavering]

On the subject of Auto-Instantiation (or, behavior as a function of the My.Forms object as Microsoft like to call it) I have just spent a couple of days trying to solve a problem. To be specific I had:

Friend frmOffice As New frmOffice

Public Sub Main()
...
  frmOffice.Show()         ' This reads values from the Registry and sets buttons in frmOffice
...
End Sub

Private Sub frmReception_Load(sender As System.Object,  e As System.EventArgs) Handles MyBase.Load
...
  blnMode = frmOffice.Rad01.Checked
...
End Sub

What I found was that although frmOffice was on display and the setting was clearly made as "True", blnMode was showing "False". After a lot of messing about it became apparent that there were TWO versions of frmOffice in existence. One auto instantiated by Microsoft (thanks for nothing) and one by me!

So, I got rid of "Friend frmOffice As New frmOffice" and suddenly it all worked as it should ...