Disallow Multiple Instances of an app and focus to first instance?

[VBCrazyCoder]

I know how to only allow 1 instance (using a mutex). But I don't know how to bring focus to the original application (main form) when the user tries to open a new instance. Anyone know how?

[Edneeis]

I don't have any code handy at the moment but I believe its AppActivate or some such.

[Lunatic3]

A while back i tried to find a way to get the Mutex owner process name or ID but i couldnt figure out how.

[Edneeis]

http://www.vbcity.com/forums/topic.a...tex%7Cinstance

[Lunatic3]

Thanks Edneeis,
It has recommended this:

'Only works if the title of the application is the same as the ProductName.
AppActivate(Application.ProductName)

But still not a guranteed way. What is needed is the Proccess ID of the Mutex Owner.

[Edneeis]

Yes or the title of the application to activate, but I haven't had to deal with that yet. I so far have always known the title of the application.

[VBCrazyCoder]

My title is also always constant, so the link is exactly what I was looking for. I put the AppActivate("xxxxx") around a Try Catch just to be sure.

But I would much rather use the ProcessID as suggested. Now, on to figuring our how to get the ProcessID...

[Lunatic3]

Hey man, I didn't notice you have recommended that in that forum.

[RSJIG]

It has been a long time since you asked for this. I was just browsing and thought I would pass this along. You wanted to activate by Process ID. Since Process.GetProcessesByName(Process.GetCurrentProcess.ProcessName).Length returns >1, if the application is already open, you must compare the current process id to the ones found to figure out which one to activate. Hope this helps anyone.

Dim current As Process = Process.GetCurrentProcess()
 
        Try
            If Process.GetProcessesByName(Process.GetCurrentProcess.ProcessName).Length > 1 Then
                Try
                    For i As Integer = 0 To (Process.GetProcessesByName(Process.GetCurrentProcess.ProcessName).Length - 1)
                        If (Process.GetProcessesByName(Process.GetCurrentProcess.ProcessName)(i).Id) <> current.Id Then
                            AppActivate(Process.GetProcessesByName(Process.GetCurrentProcess.ProcessName)(i).Id)
                        End If
                    Next
                Catch ex As Exception
                    ' Add code as desired
                End Try
                Return True
            Else
                Return False
            End If
        Catch ex As Exception
            Return False
        End Try

[Lunatic3]

Thanks RSJIG for the suggestion. But I'm afraid the main problem which was getting the process name or ID of a mutex owner still remains. This post is about 4 years old and back to .NET FX 1.0 time. So there might be ways in newer frameworks.