if you have that library what is the problem?
How to add the reference? THis can't be your question, but if it is, put the required dlls in a local bin directory accessible to the web app, and in your project right click add reference... then a using statement and you probably are ok.
Is it not a dotnet dll? With that example, it appears that it is.
If not, you might create a separate C# lib
project where you create method calls to wrap the dll method calls and then use that lib you create.
Is it a C DLL you have to call?
stuff like
[DllImport("fred.dll", SetLastError =
true)]
public static
extern bool clyde(int i,
ref double precision);
or is it an activeX DLL?
might do something like this
private System.Type objESS = System.Type.GetTypeFromProgID("ESS.FindWhatToPutHere");
private dynamic objESS;
and later in the constructor or wherever first used, check for null and
if (objESS==null)
objESS = System.Activator.CreateInstance(objCMtype);
To find the programID for the correct string for ESS.FindWhatToPutHere, I often still used VB6 and added a reference, then used object explorer...
or
http://stackoverflow.com/questions/262134/how-can-i-browse-the-classes-and-methods-of-an-activex-dll
http://www.softpedia.com/get/Programming/Other-Programming-Files/COM-Explorer.shtml
I'd often first use a COM InterOp - just add a reference to the required dll
so you get the calls and parameters correct
when done, switch back to the .net 4 dynamic as above because it often works better
http://www.dotnetspider.com/resources/423-How-To-Call-ActiveX-DLL-Net-Environment.aspx
I guess don't understand the question or the problem.