Application Instance Already Open ?

[Krogoth]

Hi Gurus,

How can I prevent my application from being opened more than once ?

Thanks,
Krogoth!

FSM

[enjoy@mind]

There are two techniques to achive this:

1) Using windows API

Const ERROR_ALREADY_EXISTS = 183&
private Declare Function CreateMutex Lib "kernel32" Alias "CreateMutexA" (lpMutexAttributes as Any, byval bInitialOwner as Long, byval lpName as string) as Long
private Declare Function ReleaseMutex Lib "kernel32" (byval hMutex as Long) as Long
private Declare Function CloseHandle Lib "kernel32" (byval hObject as Long) as Long
private Sub Form_Load()
Dim hMutex as Long
hMutex = CreateMutex(byval 0&, 1, App.Title) 'Try to create a Mutex

'Check the mutex already exist or not
If (Err.LastDllError = ERROR_ALREADY_EXISTS) then
'Clean up all
ReleaseMutex hMutex
CloseHandle hMutex

'More than one instance detected
MsgBox "Give your Message"
End
else
'form load code
End If
End Sub





2) Using VB App global Object

private Sub Form_Load()
If App.PrevInstance = true then MsgBox "Give your Message": End
End Sub





programmer at MIND

[Cimperiali]

You should not use "End" keyword...

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and all the other wonderful people who made and make Codeguru a great place.
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The Rater

[Boumxyz2]

2) Using VB App global Object ( Corrected )


private Sub Form_Load()
If App.PrevInstance = true then
MsgBox "Your Message"
Unload me
End Sub




Nicolas Bohemier
______________

Un sourire ne coûte rien, mais il rapporte beaucoup; il enrichit celui qui le reçoit sans appauvrir celui qui le donne.

Frank Irving Fletcher

[Krogoth]

Thanks Man...

I will use the second one but will try the first one too ;-)

Krogoth!

FSM