Prevent opening second instance software

[JohnPapa]

I would like to prevent the user from opening more than one instances of a certain software that is written in Access and uses Jet as the db. Any ideas?

 

[JohnPapa]

I just want to add that I am talking about a multi-user db that is accessed from other PCs. I just want one instance max per PC.

 

[Simon_MT]

Try this Function:

Function IsRunning() As Integer
    DoCmd.Maximize
    Dim db As DAO.Database
    Set db = CurrentDb()
        If TestDDELink(db.Name) Then
           MsgBox "The database is already open"
           Application.Quit
           Set Application = Nothing
        End If
End Function

Simon

 

[mdlueck]

Try this Function:

        If TestDDELink(db.Name) Then

That LOC comes up with warning that TestDDELink() is an undefined function.

Intriguing suggestion, kindly supply that function please.

 

[mdlueck]

Intriguing suggestion, kindly supply that function please.

I found at least one reference:

"warding off multiple instances of Access"
http://www.tek-tips.com/viewthread.cfm?qid=118359

Odd that they return True / False as data type Integer. I implemented it as Boolean and it works. Thanks for the suggestion!

 

[mdlueck]

Since this suggestion has verified existence of the database application already running, could I easily add after displaying the warning message sending Restore or Maximize to the other instance before exiting?

It has been many MANY years since I coded DDE...

 

[mdlueck]

Ddduuuaaa... Not possible to communicate with the other instance of Access / same database, the DDEInitiate had an error!

If it had not gotten the error, this looks to be the correct DDE method to Maximize the entire Access window:

DDEExecute varDDEChannel, "[DoCmd.RunCommand acCmdAppMaximize]"

 

[JohnPapa]

Many thanks for all your help.
John