Problem with Sub Main

[kalaHasti]

I have a sub Main() as the start up for my project.

Module Module1
    Public Sub Main()
        Dim myForm As New FrmLogin()
        'do something
        myForm.Show()
        myForm.Activate()
    End Sub
End Module

It shows the FrmLogin, and then the application exits.
Why it happens like this and how to make the application to run?

I have place the typical login entry controls in the FrmLogin form, with no code written by me.

[pvbangera]

u need to show the form by using showdialogue method

Module Module1
    Public Sub Main()
        Dim myForm As New FrmLogin()
        'do something
        myForm.ShowDialogue()
    End Sub
End Module

[kalaHasti]

Thanks pvBangera, it solved the problem.
So confusing, in VB we needed only to call the .Show() method....

[taxes]

Hi,

"Module Module1
Public Sub Main()
Dim myForm As New FrmLogin()
'do something
myForm.ShowDialogue()
End Sub
End Module"


Not good. That way MyForm will have to stay open. A better way is to replace
myForm.ShowDialog

with

Application.Run(myForm)

[salvelinus]

There's also a scope issue. You can declare the form as a global variable in the module, then .show() in sub main will work.

[taxes]

Hi salvelinus



"There's also a scope issue. You can declare the form as a global variable in the module, then .show() in sub main will work."

Not in my copy of VB.NET. Have you tried it?

[salvelinus]

Originally posted by taxes
Hi salvelinus



"There's also a scope issue. You can declare the form as a global variable in the module, then .show() in sub main will work."

Not in my copy of VB.NET. Have you tried it?

Yes, the other day. I've got VB 2002. If I declared the form in Sub Main, then did Application.Run, the form would briefly flash into existance, then disappear. The app would still be listed as running, according to the IDE, but no forms were visible. My maybe faulty assumption is that it was a scope issue, because when I declared the form as global, it worked fine. It also allowed me to access/manipulate values on the form from other forms.
If the event/function/procedure where the form is declared doesn't exit until the form is closed, then you're ok. But if you need the form after the e/f/p, you're out of luck.

private sub DoSub()
   dim frmX as New frmOtherForm
   dim i as integer
'yada yada
Exit Sub

i is out of scope once Exit Sub executes. Shouldn't it be the same for frmX?

[taxes]

Hi Salvelinus,

"Yes, the other day. I've got VB 2002. If I declared the form in Sub Main, then did Application.Run, the form would briefly flash into existance, then disappear. "

Yup! That is why I said it does not work


"The app would still be listed as running, according to the IDE, but no forms were visible. "

No. The application ends and you are back in the Design environment.


" My maybe faulty assumption is that it was a scope issue, because when I declared the form as global, it worked fine. "

If you use Form.Show in the Sub Main, it does not matter whether you declare the Form public or otherwise. The result will still be that the form flashes and the programme ends. You either use Form.ShowDialog or Application.run(Form)


"It also allowed me to access/manipulate values on the form from other forms."

I can't understand this. The programme has finished and nothing is accessible. I am obviously misunderstanding you.


"If the event/function/procedure where the form is declared doesn't exit until the form is closed, then you're ok. But if you need the form after the e/f/p, you're out of luck. "


Understood, but you are not going to design the application to perform one routine.

"i is out of scope once Exit Sub executes. Shouldn't it be the same for frmX?"

Certainly. But we are talking about starting from a module Sub Main


I think the best practice is to use the Application.Run method in a Sub Main. This then gives you total freedom.


Can any of you guys please say if I am wrong and also tell me why when the form which starts the application, whether from a module Sub Main or not, is closed, all other forms close - unless those other forms were opened with a ShowDialog method in the Sub Main?

Regards,