Create DLL+Calling unmanaged dlls dynamically in C#.NET

dont forget to mark this as accepted answer
it will help me

Thank you very much

See the articles under http://www.codeproject.com/dll/#Beginners - especially http://www.codeproject.com/dll/EasyDLL.asp ("Super Easy DLL") and http://www.codeproject.com/dll/DLL_EZ_Build_EZ_Usage.asp ("Making DLLs easy to build and use") which are both compact and will give you a jump start on this issue

and how can I export this project to a dll?

In visual Studio there are Options when you start new project there is option for building class library