C#

using System;
using System.IO;
using System.Collections.Generic;
using IntroCS;


namespace GradeProgram {

    class Gradebook {

        static void Main()
        {


            string fileName = UIF.PromptLine ("Please enter the comp course with no spaces: ");
            string categoryFileName = "categories_" + fileName + ".txt";
            var reader = new StreamReader (categoryFileName);

            while (!reader.EndOfStream) {
                string line = reader.ReadLine ();
                Console.WriteLine (line);

            }
        }

            string studentFileName = "student_" + fileName + ".txt";

            var reader2 = new StreamReader (studentFileName);
            while (!reader2.EndOfStream) {
                string student = reader2.ReadLine ();
                Console.WriteLine (student);
        }

        }

        static string[] GetStringArray(string input)
        {
            string[] parts = input.Split(',');
            return parts;
        }

        static int[] GetIntArray(string input)
        {
            string[] parts = input.Split(',');
            int[] intparts = new int[parts.Length];
            for (int i = 0; i < parts.Length; i++)
                intparts[i] = int.Parse(parts[i]);
            return intparts;
        }

        static int codeIndex(string code, string[] categories)
        {
            for (int i = 0; i < categories.Length; i++)
            {
                if (categories[i].StartsWith(code))
                {
                    return i;
                }
            }
            return -1;
        }

        static string[] GetCatNames(string file)
        {


            var reader = new StreamReader(file);

            string categories = reader.ReadLine();
            string[] catnames = GetStringArray(categories);
            for (int i = 0; i < catnames.Length; i++)
                Console.WriteLine("Category at position {0} = {1}", i, catnames[i]);
            return catnames;
        }

        static int[] GetWeights(string file)
        {

            int targetLine = 2;
            int counter = 1;
            int[] weightvalues = new int[0];
            var reader = new StreamReader(file);
            while (!reader.EndOfStream)
            {

                string weights = reader.ReadLine();
                if (counter == targetLine)
                {
                    weightvalues = GetIntArray(weights);
                }
                counter++;
            }
            for (int i = 0; i < weightvalues.Length; i++)
            {
                Console.WriteLine("Category at position {0} = {1}", i, weightvalues[i]);
            }
            return weightvalues;

        }

        static int[] GetNumOfItems(string file)
        {
            int targetLine = 3;
            int counter = 1;
            int[] itemsvalues = new int[0];
            var reader = new StreamReader(file);
            while (!reader.EndOfStream)
            {
                string items = reader.ReadLine();
                if (counter == targetLine)
                {
                    itemsvalues = GetIntArray(items);
                }
                counter++;
            }
            for (int i = 0; i < itemsvalues.Length; i++)
            {
                Console.WriteLine("Category at position {0} = {1}", i, itemsvalues[i]);
            }
            return itemsvalues;
        }

        static string[] GetStudent(string file)
        {

            var reader = new StreamReader(file);
            //string student = reader.ReadLine();
            //string[] studentnames = GetStringArray(student);
            //int targetLine = 3;
            //int counter = 1;
            //string[] itemsvalues = new string[0];

            while (!reader.EndOfStream)
            {
                string items = reader.ReadLine();
                //if (counter == targetLine)
                //{
                string[] itemsvalues = GetStringArray(items);
                for (int i = 0; i < itemsvalues.Length; i++)
                    Console.WriteLine("Category at position {0} = {1}", i, itemsvalues[i]);
                //}
                //counter++;
            }

            //return studentnames;
            return null;


        }

        }}

HttpContext.Current.Response.Clear(); //clear anything in io buffer
           Response.ClearContent();
           HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment;filename=GrpFile.xls");
           HttpContext.Current.Response.Charset = "";
           HttpContext.Current.Response.ContentType = "application/vnd.ms-excel";
           StringWriter sw = new StringWriter();
           HtmlTextWriter hw = new HtmlTextWriter(sw);
           HtmlForm frm = new HtmlForm();
           gvCampGrp.Parent.Controls.Add(frm);
           frm.Attributes["runat"] = "server";
           frm.Controls.Add(gvCampGrp);
           frm.RenderControl(hw);
           HttpContext.Current.Response.Write(sw.ToString());
           HttpContext.Current.Response.End();

public override void VerifyRenderingInServerForm(Control control)
     {
         /* Confirms that an HtmlForm control is rendered for the specified ASP.NET
            server control at run time. */
         return;
     }