Calling VB 6.0 Function from C# .Net

[sakthikumarb]

Hello All,
I am having vb 6.0 ActiveX dll contains one method

Public Function GetHandleCount() As String
Set objRefresher = CreateObject("WbemScripting.SWbemRefresher")
Set objServicesCimv2 = GetObject("winmgmts:\\" _
    & "." & "\root\cimv2")
Set objRefreshableItem = objRefresher.AddEnum(objServicesCimv2, "Win32_PerfFormattedData_PerfProc_Process")
objRefresher.Refresh
strf = Format(Now, "dd-MMM-yyyy HH:nn:ss") & "." & Right(Format(Timer, "#0.000"), 3)
  For I = 1 To 2
 objRefresher.Refresh
    For Each Process In objRefreshableItem.ObjectSet
 
        If Process.Name = "_Total" Then
          strf = strf & "  " & Process.HandleCount
      End If
    Next
Next
 GetHandleCount = strf
End Function
 

In C#.Net console application i added this vb 6.0 dll and crated the object to that and then try to access GetHandleCount() method.

 Project1.VBCls obj = new Project1.VBCls();
 Console.WriteLine(obj.GetHandleCount());
 

Please find my next post for question...

[sakthikumarb]

Post Cont...


When I run the C#.NET application getting the exception
An unhandled exception of type 'System.Runtime.InteropServices.COMException' occurred in HandleCountSample.exe
Additional information: Exception from HRESULT: 0x80041003.

what is the solution of this error.
I observed that This line is giving exception
Set objRefreshableItem = objRefresher.AddEnum(objServicesCimv2, "Win32_PerfFormattedData_PerfProc_Process").

Please give me any solution.

[Plater]

Well, I don't know why you are using an old VB DLL, when WMI is fully supported in .NET, but don't you need to use DLLImport when using an unmanaged resource like your VB DLL?

[sakthikumarb]

Well, I don't know why you are using an old VB DLL, when WMI is fully supported in .NET, but don't you need to use DLLImport when using an unmanaged resource like your VB DLL?

Thanks for your reply.

I think there is no Refresh method in C#.Net like SWbemRefresher.Refresh . Do you know any equivalent method for that in C#.Net to refresh the Objects.
to make use of Refresh method I am calling vb 6.0 method in C#.Net.
I Tried with DllImport also, It is giving the error "entry point not found" in vb 6.0 dll . If you have any solution for this, please provide that steps.

[Plater]

When you use the DLL with DLLImport, you have to specify which public functions/objects you want to use I think.

And what do you mean by "refresh"? Just running the query again?

[Frinavale]

Thanks for your reply.

I think there is no Refresh method in C#.Net like SWbemRefresher.Refresh . Do you know any equivalent method for that in C#.Net to refresh the Objects.
to make use of Refresh method I am calling vb 6.0 method in C#.Net.
I Tried with DllImport also, It is giving the error "entry point not found" in vb 6.0 dll . If you have any solution for this, please provide that steps.

What does the "Refresh" method do?

It sounds like you are going to have to Marshal your VB 6 code so that .NET knows how to use it properly.

It would really simplify your life if you could just write a method in .NET that "Refreshes" your objects instead of using unmanaged code to do this.

-Frinny

[sakthikumarb]

What does the "Refresh" method do?

It sounds like you are going to have to Marshal your VB 6 code so that .NET knows how to use it properly.

It would really simplify your life if you could just write a method in .NET that "Refreshes" your objects instead of using unmanaged code to do this.

-Frinny

Please check this link which talks about the "Refresh" method. It Updates information. http://msdn.microsoft.com/en-us/library/aa392091(VS.85).aspx

When I use the DLL with DLLImport, how and where to specify the public functions/objects that I want to use.

[zubair1]

When I use the DLL with DLLImport, how and where to specify the public functions/objects that I want to use.

[DllImport("MyDLL.dll", CharSet = CharSet.Unicode)] 
public bool MyFuncEx(string exName) 
{ 
}
 

[Plater]

The refresher sounds just like you are receiving an event from WMI. That can be done as well in .NET

[andyuk0000000000]

You should just be able to add a project reference to the com dll, Doing this will invoke the type library importer and create a callable wrapper for you COM library. The you can just use it. You dont need to get into writing you own interop signatures when you only using basic types.