Disallowing Multiple Instances Of VB Project

[Gettoblaster]

Hello -- <br>
<br>
I have tried the app.previnstance in order to end the project (if there is one already open) but the problem is that the app.previnstance always = false no matter how many instances of the project i have open. I use the app.previnstance command in the mainmodule sub main. does anybody have any ideas???

 

[Logit]

Nothing specific, unless the version of VB you are running needs to be wiped from your hard drive and reloaded. Sounds funny I know, but on several occasions recently I have had VB doing things it shouldn't or NOT doing things it should and a simple reload cleared up the problems. Not all of the problems, but most.<br>
<br>
I was looking through my code library and found the following source sample but you said it isn't working for you .... so I am at a loss ! <br>
<br>
If App.PrevInstance Then<br>
MsgBox (&quot;Cannot load program again.&quot, _<br>
vbExclamation, &quot;The requested _<br>
application is already open&quot;<br>
Unload Me<br>
End If<br>
<br>
Jim <A HREF="mailto:jdmcjen@stc.net">jdmcjen@stc.net</A>

 

[Snaggs]

This was posted some time back, I don't remember by who, but here's the information you need. This is not the one that was posted but one we have been using for about 2 years now.<br>
<br>
Declare Function FindWindow Lib &quot;user32&quot; Alias &quot;FindWindowA&quot; (ByVal lpClassName As String, ByVal lpWindowName As String) As Long<br>
Declare Function SetForegroundWindow Lib &quot;user32&quot; (ByVal hwnd As Long) As Long<br>
Declare Function ShowWindow Lib &quot;user32&quot; (ByVal hwnd As Long, ByVal nCmdShow As Long) As Long<br>
<br>
Sub CheckInstance(strTitle as String)<br>
<br>
Dim lApp As Long<br>
Dim intShown As Integer<br>
<br>
'Check for a duplicate instance of the program.<br>
lApp = FindWindow(vbNullString, strTitle)<br>
<br>
'If lApp is something other than 0, then there is a current instance running.<br>
If lApp &lt;&gt; 0 Then<br>
If SetForegroundWindow(lApp) Then<br>
intShown = ShowWindow(lApp, 1)<br>
End If<br>
End If<br>
End Sub<br>
<br>
You call it from your program, by passing the information on the caption of the form.<br>
<br>
CheckInstance &quot;Insuarance Claims Processing Module&quot;<br>
<br>
Be sure the caption of your form has the same spelling as what you use in the call to CheckInstance.<br>
<br>
Steve<br>
<A HREF="mailto:sdmeier@jcn1.com">sdmeier@jcn1.com</A>

 

[Alt255]

Also, Edderic posted a very handy method for identifying all running apps. You can find it in the VB 5&6 thread marked &quot;Unauthorized Applications&quot; (2/3).