Use VB6 dll in c#

I have created VB6 Project of ActiveX dll type added two function

Public Function Name(aName As String)
MsgBox ("Your Name is " & aName)
End Function
Public Function TestName(aName As String) As String
TestName = " Hello " & aName
End Function

Created DLL from same Project.

Then created Wrapper using below command .

C:\Program Files (x86)\Microsoft SDKs\Windows\v10.0A\bin\NETFX 4.6.1 Tools>TlbImp.exe C:\Test\TestActiveX\Project1.dll /out: C:\Test\TestActiveX\out\Project1.dll

If i am performing only above operation then i am not getting Project1.dll under COM section but then i am registering dll using below code

C:\WINDOWS\system32>regsvr32 C:\Test\TestActiveX\Project1.dll

then only i am getting dll under COM section inside VisuaL studio Add Reference Dialog

i tried adding reference from C:\Test\TestActiveX\out\Project1.dll folder also but every time i am getting runtime error as below.

System.Runtime.InteropServices.COMException: 'Retrieving the COM class factory for component with CLSID {ID} failed due to the following error: 80040154 Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG)).'

public string ReturnFromCOM()
{
TestClass testClass = new TestClass();
return testClass.TestName(" Hello ");
}

i am not able to get it done, don't know what is missing in this steps. My Windows OS : 64 bit Windows 10 Framework 4.6.1 as well as 4.8.1 but created console application with Framework 4.6.1

i tried even changing project target to x64/x86/anyCPU but it's not working at all.

2 Replies

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Viken Patel6y ago
it has resolved by this link there was no need to use tlbimp.exe for wrapping in .net application
https://www.codeproject.com/Questions/5255105/How-to-use-vb6-DLL-function-in-Csharp-NET-using-4
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Rajanikant Hawaldar6y ago
Please change your project build properties Platform target from Any CPU to x86 or x64 based on your system and it may fix the issue.The VSS Interop is a managed assembly using 32-bit Framework and the dll contains a 32-bit COM object. If you run this COM dll in 64 bit environment, you will get the error message. https://stackoverflow.com/questions/17985653/class-not-registered-error
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