https://barnamenevis.org/showpo...7&postcount=71

این تغییرات را در کلاس مربوط به StartUp برنامه اعمال کنید :
کد:


Imports System.Diagnostics



Class Program



    <STAThread()> _

    Shared Sub Main()



        If IsPrevInstance() Then

            Return

        End If

        Application.EnableVisualStyles()

        Application.SetCompatibleTextRenderingDefault(Fals  e)

        Application.Run(New Form1())

    End Sub



    Private Shared Function IsPrevInstance() As Boolean

        Dim processName As String = Process.GetCurrentProcess().ProcessName

        Dim instances() As Process = Process.GetProcessesByName(processName)

        If instances.Length > 1 Then

            Return True

        Else

            Return False

        End If

    End Function



End Class