How to Open a File Without Prompting User in Same Directory With C# Windows Form Application

I am attempting to open a file within the same directory as my main project, and I was wondering if someone could tell me the syntax for opening a simple *.txt file that is within the same working directory as your Windows form executable file. I am attempting to open the file without having the user have to select a file to preload a set of values into memory. Any help that you could provide with this question would be greatly appreciated.