check if application is already opened

[luca90]

My first VB6 project!

but my first very big prob!

I have compiled my project with name MYPrg.exe.

Now if a user re-click on the icon "MYPrg" the user open twice the app!!!!

Is possible if the application MYPrg.exe is already opened, appear a Msgbox (Attention the application is alredy run on this PC)...
How to?

[Witis]

Use app.prevInstance in the startup section of your app:

If App.PrevInstance Then ' insert your code to exit gracefully

[luca90]

Use app.prevInstance in the startup section of your app:

If App.PrevInstance Then ' insert your code to exit gracefully

ok tks...

I use this in Form_Load event of main form:

If App.PrevInstance Then
        MsgBox "Application already active!", vbInformation
        Unload Me
    End If

but when i click OK on msgbox i have this error in image:

[Witis]

That is definitely not the Application already active! msgbox you added, so you will need to step through your startup code to trace the error.

To step through your code:
1. Insert a stop point. Left click in the margin to the left of a line of code in your startup procedure. You will be able to see a red dot indicating a stop point is visible.
2. Then run your application. It will stop at the break point you just created.
3. Now step through your code a line at a time using the F8 button. Note you can use shift + F8 to skip over a call to a subroutine or a function.

Don't forget to remove the stop point when you have finished by left clicking the red dot you created in the margin.

[luca90]

That is definitely not the Application already active! msgbox you added, so you will need to step through your startup code to trace the error.

To step through your code:
1. Insert a stop point. Left click in the margin to the left of a line of code in your startup procedure. You will be able to see a red dot indicating a stop point is visible.
2. Then run your application. It will stop at the break point you just created.
3. Now step through your code a line at a time using the F8 button. Note you can use shift + F8 to skip over a call to a subroutine or a function.

Don't forget to remove the stop point when you have finished by left clicking the red dot you created in the margin.

Tks! But i have resolved with:

Private Sub Form_Load() 

If App.PrevInstance Then

        MsgBox "APPLICAZIONE *** " & App.Title & " *** GIA' IN ESECUZIONE!", vbInformation

        End

    End If
    

End Sub

[Witis]

Be careful, the End statement can sometimes cause problems, unloading is the safer way to go: http://www.a1vbcode.com/vbtip-148.asp