mixed c#, c++ application

I wondered if anyone could possibly point me in the right direction as i’ve managed to confuse myself alot recently reading lots of different articles about how to do this…

I have several working console applications written in C++. I want to make an application with a UI, preferably using WPF or something which would mean c# where I can’t use CUDA. I have read several articles regarding compiling c++ as a dll and invoking this from c# but I just don’t quite understand how it would work with regards to importing all my data and outputting lots of different results. (The program does image alignment for a series of microscope images at different focii, so it starts by importing a load of images, takes a few parameters, then runs through outputting drift and focal seperation for each image).

Could anyone quickly go over the basics of how to do this and then I will try making a ridiculously simple example to see if I can do that.