Most of the examples shows how to read text file from exact location (f.e. \"C:\\Users\\Owner\\Documents\\test1.txt\"). But, how to read text files without writing full path
If your application is a web service, Directory.CurrentDirectory doesn't work.
Directory.CurrentDirectory
Use System.IO.Path.Combine(System.AppDomain.CurrentDomain.BaseDirectory, "yourFileName.txt")) instead.
System.IO.Path.Combine(System.AppDomain.CurrentDomain.BaseDirectory, "yourFileName.txt"))