VB Snippet - Proper way to Exit your Application

[James Stanich]

Dim frm as Form 
 
For Each frm in Forms 
 
Unload frm 
 
Set frm=Nothing 
 
Next 
 
End

[Darkolord]

_

[phrozeman]

Who said he uses timers?

[Darkolord]

oooops i'm sorry i didn't see that "End" at the end...

[James Stanich]

Have you tested this theory?

[phrozeman]

Yeah, works perfect

[Nightwalker83]

Originally posted by James Stanich
Have you tested this theory?

You could put:

app.taskvisible = false

instead of:

END

[VictorB212]

if you use "End" you had better be sure that you close any resources that you open via API's or dll's...

[phrozeman]

Originally posted by Nightwalker83
You could put:

app.taskvisible = false

What does that have to do with closing ur application?
It's just to hide ur app from the windows tasklist

[Nightwalker83]

Originally posted by phrozeman
What does that have to do with closing ur application?
It's just to hide ur app from the windows tasklist

Using:

Unload me

or

unload f

Would just unload the application but it would still show in the windows tasklist.

[snakeeyes1000]

true, but i would still recommend using End instead of taskvisible. end does more than just removing the app from tasklist, which once the forms are unloaded properly, is a good thing

[VictorB212]

Err, that only happens if you terminate your application in a bad way, or your computer is majorly screwed up, because I've never needed it...

You'd want app.taskvisible=false if it takes a while to unload and you don't want your average user to notice. However, it does nothing with respect to unloading your program.

[Nightwalker83]

Originally posted by snakeeyes1000
true, but i would still recommend using End instead of taskvisible. end does more than just removing the app from tasklist, which once the forms are unloaded properly, is a good thing

Using:

END

Is always bad practise because your program would crash.

You'd want app.taskvisible=false if it takes a while to unload and you don't want your average user to notice. However, it does nothing with respect to unloading your program.

I know but I have always had my application still show in the task window after I have closed it using:

unload me 'Or whatever

I just add:

app.taskvisible=false

To make sure I don't get this problem after the program finishes.

[VictorB212]

The problem with using app.taskvisible = false is that it won't unload your application! It'll only make it seem like it has been unloaded.

If it isn't unloading when you do unload me, then you need to make sure that no functions being called after "unload me" are referencing any forms or anything in or on forms.

Go ahead and attach a simple project where after the "unload me" statement (and ALL the forms have to be unloaded, not hidden), it does not disappear from the taskbar.

[Nightwalker83]

The problem with using app.taskvisible = false is that it won't unload your application! It'll only make it seem like it has been unloaded.

I meant use it like this:

Private Sub Command1_Click()
App.TaskVisible = False
Unload Me
End Sub

On some computers the application name stayed in the Task List after using:

unload me

That why I added it in I am NOT say you have to use it though.

[Pc_Madness]

Yep, definately a good point Aaron.

I would also recommend chucking a Form.Visible = false line as well, makes for a slightly smother affect when a program closes.

[Zealot]

Ok, so, how's the VB.Net version of James' code?

[VBGuy]

The reason you are needing to put app.taskvisible = false or End after a form unload is because your unload ISNT unloading and destroying the form, but leaving a reference out there that you didn't cleanup. Try putting a:

set formname = nothing

where formname is the actual form name in the unload event of the form.

Do not use

set me = nothing

If you unload the form and destroy its reference (assuming you have done the same for any other object you have created) you will not need End OR app.taskvisible = false

[Nightwalker83]

Originally posted by VBGuy
The reason you are needing to put app.taskvisible = false or End after a form unload is because your unload ISNT unloading and destroying the form, but leaving a reference out there that you didn't cleanup. Try putting a:

set formname = nothing

where formname is the actual form name in the unload event of the form.

Do not use

set me = nothing

If you unload the form and destroy its reference (assuming you have done the same for any other object you have created) you will not need End OR app.taskvisible = false

If you bothered to read the posts you would have noticed that I have already stated what you have said.

[flog3941]

So how come when I use this code in VB.net the "forms" part is underlined like an error?

[Pc_Madness]

Because this code is meant for VB6?

[flog3941]

So whats the code for "The proper way to exit an application" for VB.net, if you please.

[Skill Jaan]

why can't we use simply:

End

Why all this. I have always used only End and have not found anything wrong with it!!

[Pc_Madness]

End doesn't clean up memory used by your program and such. One of the guys will give you the list of why its a bad idea.

[PaulyWally]

How about............


___________________________

Private Sub Form_Unload()

Set Me = Nothing

End Sub
___________________________


???????

[crptcblade]

Originally posted by PaulyWally
How about............


___________________________

Private Sub Form_Unload()

Set Me = Nothing

End Sub
___________________________


???????

Well, nothing, except for the fact that it won't compile.

[PaulyWally]

Sorrrrrrrrrrrryyyyyyy.........


___________________________

Private Sub Form_Unload()

Set frmFormName = Nothing

End Sub
___________________________

[James Stanich]

Wow. What a reponse for such a simple task....

[The Hobo]

Originally posted by Skill Jaan
why can't we use simply:


Why all this. I have always used only End and have not found anything wrong with it!!

I hope you never get into subclassing.

[BrianHawley]

Originally posted by Pc_Madness
End doesn't clean up memory used by your program and such. One of the guys will give you the list of why its a bad idea.

Are you sure about that?

I mean any memory you open up yourself doing anything tricky - fair enough you should clean up afterwards, but surely VB6 does its own garbage collection for normal stuff like forms? Certainly I can't find anything in the VB samples or documentation about this (sure somebody will now prove me wrong) and it seems like an important thing to document if it's true.

We have a large and complex application that we run all day on several PC's. A timer closes it with a simple END statement each night and the PC's stay on 24/7 for the backup tape to run. If what you say is true, I would expect to see some memory getting chewed up each day - but Task Manager does not show any memory leakage at all.

Now I've set myself up as a target, somebody want to take a shot?

[The Hobo]

Here's a great reason to not use End...

Run the attached code and click the button.

Edit: Whoops. The code is located three posts down.

[crptcblade]

Originally posted by The Hobo
Here's a great reason to not use End...

Run the attached code and click the button.

Frightening...

[The Hobo]

Using End in the Form_[Query]Unload() is bad. Using it elsewhere in your application is even worse. Why?

Slap a CommandButton on your form, name it cmdEnd, and run this code:

Private Sub cmdEnd_Click()
  End
End Sub
 
Private Sub Form_Unload(Cancel As Integer)
  MsgBox "I was called!"
End Sub

What doesn't happen?

[The Hobo]

Whoops. The attached code:

[BrianHawley]

Well yes. Obviously if you go outside of native VB with a dll call to deliberately allocate memory and don't free it, of course you will have a problem.

But if you simply have a number of forms open and call End from a module, VB seems to clean up after itself.

I can't see it's possible to write a universal 'catch all' exit procedure guaranteed to clean up everything. You just have to do it on a case by case basis. And I'm not convinced you need to set any open forms to Nothing before Ending, so long as the End statement is not inside one of them. Vb seems to do that automatically. At least that is what experimentation seems to show. Anyone got sample code to demonstrate to the contrary?

[hothead]

Easy way around that...

Just make the call BEFORE you send End.

Private Sub cmdEnd_Click()
    Form_Unload
End Sub
 
Private Sub Form_Unload()
    Unload Me
    MsgBox "I was called"
    End
End Sub

[crptcblade]

I think this has been beaten to death, wouldn't you say?

[BrianHawley]

Originally posted by crptcblade
I think this has been beaten to death, wouldn't you say?

I agree. This threads nearly as long as your signature

[The Hobo]

Originally posted by hothead
Easy way around that...

Just make the call BEFORE you send End.

Private Sub cmdEnd_Click()
    Form_Unload
End Sub
 
Private Sub Form_Unload()
    Unload Me
    MsgBox "I was called"
    End
End Sub

Now that's just redundant if you ask me. If the Form_Unload() has been called, your application will end afterwards. So why call End?

[hothead]

That was supposed to be Form_QueryUnload.

If you look on Planet Source Code, search for BFChat, and look under the same sub inside the Client portion (bfcc.vbp I think it is), you'll see an example of this in action.

If the user tries to exit while it's trying to connect, the program displays a message box telling you to wait. It doesn't call End yet until either it's completely connected, or fails to connect.

If the user tries to exit, and the winsock state is not trying to connect, it will just exit as usual. Then look in your Task Manager if you're running XP. You will find that it's not under the Applications or Progresses tabs anymore. It has freed up the memory used by the program, as it's supposed to do.

Granted the dude's code's a bit messed up (it takes some doing to figure out what the variables he used are for), but I think this is a good example of how you can do what you tried to do in your End.vbp file.