stathread

 <STAThread()> Public Shared Sub Main()

            If CommFunc.PrevInstance() Then

                MsgBox("本程序已经运行。")
                Exit Sub

            End If

            Application.EnableVisualStyles()

            Dim config As System.Configuration.Configuration = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None)
            Dim connString As System.Configuration.ConnectionStringsSection = config.ConnectionStrings

            If connString.ConnectionStrings("tipdm2008") IsNot Nothing Then
                connString.ConnectionStrings("tipdm2008").ConnectionString = ""
            End If

            connString.SectionInformation.ProtectSection("RsaProtectedConfigurationProvider")

            connString.SectionInformation.ForceSave = True
            config.Save(ConfigurationSaveMode.Modified)

            Dim frmLogin As New FrmLogin

            frmLogin.MessageToolSelect = True
            frmLogin.LoginType = Thit.TiPDM.Common.Declare.LoginType.TiPDM
            frmLogin.ShowDialog()

            If frmLogin.DialogResult = Windows.Forms.DialogResult.Cancel Then
                Exit Sub
            End If
            frmLogin.Dispose()

            Application.Run(New FrmMain)

        End Sub

原文地址:https://www.cnblogs.com/aloha/p/1254998.html