ikinci uygulama

Exe'yi çalıştırırken bir örneğinin açık olup olmadığını kontrol edersin, eğer başka bir örneği açıksa, mevcut exe'yi kaparsın.

Kontrol için : Process.GetProcessByName(your exe process name); metodunu

Uygulamayı kapatmak için de : Application.Exit(); 'i kullanabilirsin. 

Örnek :

Imports System.Diagnostics 
Module SingleInstance

   'Entry point for the application. Main checks for a prior instance and closes

   'this one if it finds a prior one running.

   Public Sub Main() 

        If CheckForDuplicateProcess("MyAppName") Then
            Dim dupProcess As String
            dupProcess = "There is another instance of MyAppName" & _
        " running on this machine." & vbCrLf & _
        "This new instance must close." & vbCrLf & vbCrLf & _
        "Only 1 instance of MyAppName can exist" & _
        " on a machine." & vbCrLf & vbCrLf
            
        MsgBox(dupProcess, MsgBoxStyle.Critical, "Duplicate Process Detected") 

            Application.Exit() 

        Else 
                 '*** Change The FormName Below **

                 'Change the name of the form to load, to the one 

                 'applicable for your application

            Application.Run(New MainForm)
    End If 


   End Sub




   'Determines if there already is a 'processName' running in the local host.

   'Returns true if it finds more than 'one processName' running

   Private Function CheckForDuplicateProcess(ByVal processName As String) As Boolean
        'function returns true if it finds more than one 'processName' running

        Dim Procs() As Process
        Dim proc As Process


    'get ALL processes running on this machine in all desktops

    'this also finds all services running as well.


         Procs = Process.GetProcesses()
         Dim count As Integer = 0
         For Each proc In Procs
             If proc.ProcessName.ToString.Equals(processName) Then
                count += 1
             End If
         Next proc
        If count > 1 Then
             Return True
         Else
            Return False
         End If
     End Function
 End Module