Failed to call Engine.StartLoginLogoutCallback to display user login dialog in C# code

Question

I'm upgrading our custom operator interface using C# running in NET 2.0. I use Microsoft Windows Forms controls for building GUI. TestStand version is 3.1. I grab TestStand Engine Class ActiveX Control from toolbox in to the form just as I did before in my VB project. In the project references list, AxTS and TS are added in. I can call TestStand API functions through the engine object, for example I can load sequence files, create property objects, get engine properties. But when I call engine's StartLoginLogoutCallback(false, true), the user login dialog is not displayed as expected. By tracing into UI message handler code, I do not see execution start and execution end UI message, which means the fontend callback sequence is not executed or is not executed properly. I doubt that calling engine's NewExecution in my code will also have problem though I haven't tested. Has anybody encountered same problem before? Thanks for any answer in advance.

Answer 1

Hi Manooch,
Thank you very much for the help. I tried Engine.CallFrontEndCallbackEx, but it still doesn't work for me. I'm using TestStand 3.1. I created a very simple C# Windows application with Visual Studio 2005. In the toolbox of the project I Selected "Choose Items..." context menu to display the "Choose Toolbox Items" dialog. In the "COM Components" tab of the dialog I selected "TestStand Engine Class" so that I got reference to the TestStand engine in my project. The project compiles OK, The method to login/logout is as following:
 private void StartLoginLogoutCallback(bool logoutOnly, bool isInitialLogin) {    PropertyObject args = _engine.NewPropertyObject (PropertyValueTypes.PropValType_Container, false, "", 0);     args.SetValBoolean ("logoutOnly", 1/*PropOption_InsertIfMissing*/, logoutOnly);    args.SetValBoolean ("isInitialLogin", 1, isInitialLogin);    _engine.CallFrontEndCallbackEx ("LoginLogout", args, TypeConflictHandlerTypes.ConflictHandler_Error, 0); }
This method is called when the form is loaded:
 private void Form1_Load (object sender, EventArgs e) {    StartLoginLogoutCallback (false, true); }
I also tried to call StartLoginLogoutCallback method in a button click event handler, but it doesn't work either. I also notice that when I press "Exit" button which causes form's Close() method to be called, the application form does not close and I have to kill the application with task manager or to stop debugging if it is running in debug mode.
Could you please tell what's wrong? Thanks!
- cfyao