XafApplication.Security Property

static class Program {
   // ... 
   public static void Main() {
      // ... 
      MySolutionWindowsFormsApplication application = new MySolutionWindowsFormsApplication();
      application.Security = new MySecurityStrategy<User, Role>(new MyAuthenticationStrategy<User, 
         AuthenticationStandardLogonParameters>())
      // ... 
      application.Setup();
      application.Start();
      // ... 
   }
}

Friend Class Program
   ' ... 
   Public Shared Sub Main()
      ' ... 
      Dim _application As MySolutionWindowsFormsApplication = _
      New MySolutionWindowsFormsApplication()
      _application.Security = New MySecurityStrategy(Of User, Role)( _
      New MyAuthenticationStrategy(Of User, AuthenticationStandardLogonParameters)())
      ' ... 
      _application.Setup()
      _application.Start()
      ' ... 
   End Sub 
End Class