and i have the sgs_api.lib files, which i dont know how to use this file.
and i have the sgs_hlsC.DLL when i use the dependency walker i saw similar with this header. but they are in totally different name.
You need to specify the name of the DLL file to the linker. The linker is respnsible for resolving the function calls in your code to the function entry points in the DLL library.
You don't specify what IDE/compiler/linker you're using, so i can't tell you how to do that.
The names in the DLL are different because C++ "mangles" the names to encode the argument types into the function name. This allows the linker to distinguish functions which have the same name, but different argument types.