Calling functions in a DLL from an extension

Hello Rob,

Do you call the presented script code from a script extension? Please note that the DLL object you use in the code is not supported by the script extension engine. You can see the list of objects available in script extensions here.

Unfortunately, the script extension engine does not provide any straightforward way to call DLL routines. It is not designed for this purpose.

You can still call DLL routines via the dotNet object in your extensions as you used to. However, as the extension files cannot store any CRL Bridge information indeed, you may have to manually add the target DLL reference to the CLR Bridge list of any TestComplete project where you are planning to run your extension.

As for the AppDomain method, it is applied only to process objects. You can use it in your script extensions, but you need to create an application that has a reference to your DLL.

Hello Rob,

Please make sure that the routines in your DLL match the stdcall calling convention. If this does not help, please send our Support Team a sample DLL demonstrating the problem. This would help us analyze and reproduce the problem.

Also, though the script extension engine does not currently support working with DLLs via the DLL object, we have a corresponding suggestion registered in our database, and your interest in this issue has increased its rating.

I also looked into trying to use the AppDomain() approach, which needs an EXE to wrap calls to the DLL. There are no examples about how to do that. What should the EXE code look like? Which template should be used for it?

To use the AppDomain approach, you need to create an executable that loads your DLL in the application domain. For example, if you use C#, consider the following sample code:

using System.Reflection;

namespace Sample

{

  public void Main()

  {

    Assembly SampleAssembly = Assembly.LoadFrom(AppDomain.CurrentDomain.BaseDirectory + "Sample.dll");

  }

}

How does one start the EXE from an extension?

Since the script extension engine does not provide any straightforward way to start an executable, you can use the following workaround:

AppPath = "C:\\WorkFolder\\Example.exe";

WSH = new ActiveXObject("WScript.Shell");

WSH.run(AppPath);

Thank you.

Hi,



I'm confused again.

In your example of the executable that loads the DLL into an assembly ("SampleAssembly") it looks like the EXE is a console program. Doesn't it need some MessageLoop to keep the EXE active and alert for requests? How are requests for the wrappers recognized/processed in the EXE (what's the code supposed to look like for this)? What should a wrapper function look like? How does the EXE call the DLL via the SampleAssembly? It would be very helpful to have a more complete example for the necessary EXE code.

I assume that my script should be using the AppDomain approach to access this EXE, and then the EXE is to wrap calls to the DLL which has been loaded into the SampleAssembly object.

I'm sorry for asking so many questions, but there is something that I am always missing. I keep getting more little pieces of the puzzle but it's like I have been building out from the corners. The chunks are getting bigger and growing towards each other but they are still disconnected. I need the pieces that will finish connecting the chunks and make it complete/workable. It seems like it should be simple. Maybe I'm mixing pieces from different puzzles/approaches.

Hello Rob,

In your example of the executable that loads the DLL into an assembly ("SampleAssembly") it looks like the EXE is a console program. Doesn't it need some MessageLoop to keep the EXE active and alert for requests?

The sample code in my previous message belongs to the window application. TestComplete cannot access the AppDomain object of console applications. Sorry for confusing you.

As for a more detailed example of the necessary application code, you can try doing any of the following (in the examples below, I use the UserClassLib.dll library shipped along with TestComplete's Using .NET Classes example):

1. You can add a reference to your DLL into a sample application project and create an object that returns a reference to an instance of a class declared in your DLL:

using System;

using System.Windows.Forms;

using UserClassLib;



namespace DLLSample

  {

  public partial class Form1 : Form

    {

    public Form1()

      {

      InitializeComponent();

      CSalary SalaryObj = new CSalary();

      }

 

    }

  }

2. Or you can create an application containing an object that loads your DLL in the application domain:

using System;

using System.Windows.Forms;

using System.Reflection;



namespace DLLSample

  {

    public partial class Form1 : Form

    {

    public Form1()

      {

      InitializeComponent();

      Assembly SampleAssembly = Assembly.LoadFrom(AppDomain.CurrentDomain.BaseDirectory + "UserClassLib.dll");

      }

    }

  }

While the sample application is running and the SalaryObj (or SampleAssembly) object exists in the application, you can access the namespaces defined in your DLL via the AppDomain(…).dotNet property from TestComplete tests (or TestComplete’s script extensions). For example:

function Main()

{      

  var p = Sys.Process("DLLSample");

  var dotNETObj = p.AppDomain("DLLSample.exe").dotNet;



  var Salary = dotNETObj.UserClassLib.CSalary.zctor();

  Salary.Initialize(6000, 0, 0, 0);

  ...



} 

Please let us know whether any of these is helpful.

Thank you.