How to access c++ dl function in c# webservices

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I have used vb_dll.dll. It is refering to particular dll

[DllImport(@"E:\ LicenseProject\ LicenseWebServi ceProtoType\bin \vb_dll.dll",
CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true,
CallingConventi on = CallingConventi on.StdCall)]
public static extern int lp_hostid(int HostType,
StringBuilder hostidstr);


It refers particular dll but when we try to access lp_hostid() function with
proper parameter in webservices like

lp_hostid(vb_dl l_interface.HOS TID_ETHER, temp);

It is providing following error
"Attempted to read or write protected memory. This is often an indication
that other memory is corrupt."

It is working fine with web application but not in web services.

It is very urgent. Any body help is most appreciated.


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