API 32bits

How do I know when one application is runing two times?
I have the next code in 16 bits:

' Get the Handle for the RTT module
var1 = GetModuleHandle("trm0001.exe")
' Get the Reference Count of the TR module
l_int_ref_count_rtt_module = GetModuleUsage(var1)
' If an instance of SPP module is already running
If var1 > 1 Then
  MsgBox "Can not start more than one instance of TR system."
End If
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Acid_BuzzConnect With a Mentor Commented:
If you want to prevent user to load 2 instance on local pc you don't need any API call to do it you juste have to use


This VB Function return a boolean.

True : If another instance of your application is allready running on the same computer
False : if no other instance of your apps is find.

Acid Buzz.

IF you have the window's handle, you can simply check if the window exists using FindWindow.

Tell me if that's what you need,

Postel Mike
Are you trying to stop your program from running more than one instance?  If they try to start another it just transfers to the first?  If that's the case, I can tell you how to do it without any API, strictly in VB.
Nice how Acid Buzz jumps in and trys to answer the question without even knowing the question by feeding off of other people's responses.  IF you are trying to do, as I posed above, which is only allow one instance of YOUR VB app to run then yes, App.PrevInstance will tell you if there is another instance but it doesn't solve the problem of moving focus to the first instance.  To do that use AppActivate.  AppActivate takes the caption of the main form.  Since you have are calling it from within a new instance, you have to change it's caption otherwise it will only activate itself..  Here is some code.

Sub Form_Load()
  If App.PrevInstance then
    Dim OldCaption as String
    OldCaption = Caption
    Caption = ""
    AppActivate OldCaption
  End If
End Sub

That's the complete answer that I promised to give (if it is what you are looking for.)  Not the partial answer that Acid Buzz threw in there trying to leach points.
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