In Chapter 7, you modified the GreenvilleRevenue program to include a number of methods. Now, using your code from Chapter 7 Case Study 1, modify your program so every data entry statement uses a TryParse() method to ensure that each piece of data is the correct type. Any invalid user entries should generate an appropriate message that contains the word Invalid, and the user should be required to reenter the data. This is a C# program and needs to be built off of my current code but can not get this to work for some reason.

The current code is below from chapter 7 that I wrote:

using System; using static System.Console; using System.Globalization; class GreenvilleRevenue { static void Main() { const int ENTRANCE_FEE = 25; const int MIN_CONTESTANTS = 0; const int MAX_CONTESTANTS = 30; int numThisYear; int numLastYear; int revenue; string[] names = new string[MAX_CONTESTANTS]; char[] talents = new char[MAX_CONTESTANTS]; char[] talentCodes = { 'S', 'D', 'M', 'O' }; string[] talentCodesStrings = { "Singing", "Dancing", "Musical instrument", "Other" }; int[] counts = { 0, 0, 0, 0 }; ; numLastYear = GetContestantNumber("last", MIN_CONTESTANTS, MAX_CONTESTANTS); numThisYear = GetContestantNumber("this", MIN_CONTESTANTS, MAX_CONTESTANTS); revenue = numThisYear * ENTRANCE_FEE; WriteLine("Last year's competition had {0} contestants, and this year's has {1} contestants", numLastYear, numThisYear); WriteLine("Revenue expected this year is {0}", revenue.ToString("C")); DisplayRelationship(numThisYear, numLastYear); GetContestantData(numThisYear, names, talents, talentCodes, talentCodesStrings, counts); GetLists(numThisYear, talentCodes, talentCodesStrings, names, talents, counts); } public static int GetContestantNumber(string when, int min, int max) { string entryString; int num; Write("Enter number of contestants {0} year >> ", when); entryString = ReadLine(); num = Convert.ToInt32(entryString); while (num < min || num > max) { WriteLine("Number must be between {0} and {1}", min, max); Write("Enter number of contestants {0} year >> ", when); entryString = ReadLine(); num = Convert.ToInt32(entryString); } return num; } public static void DisplayRelationship(int numThisYear, int numLastYear) { if (numThisYear > 2 * numLastYear) WriteLine("The competition is more than twice as big this year!"); else if (numThisYear > numLastYear) WriteLine("The competition is bigger than ever!"); else if (numThisYear < numLastYear) WriteLine("A tighter race this year! Come out and cast your vote!"); } public static void GetContestantData(int numThisYear, string[] names, char[] talents, char[] talentCodes, string[] talentCodesStrings, int[] counts) { int x = 0; bool isValid; while (x < numThisYear) { Write("Enter contestant name >> "); names[x] = ReadLine(); WriteLine("Talent codes are:"); for (int y = 0; y < talentCodes.Length; ++y) WriteLine(" {0} {1}", talentCodes[y], talentCodesStrings[y]); Write(" Enter talent code >> "); talents[x] = Convert.ToChar(ReadLine()); isValid = false; while (!isValid) { for (int z = 0; z < talentCodes.Length; ++z) { if (talents[x] == talentCodes[z]) { isValid = true; ++counts[z]; } } if (!isValid) { WriteLine("{0} is not a valid code", talents[x]); Write(" Enter talent code >> "); talents[x] = Convert.ToChar(ReadLine()); } } ++x; } } public static void GetLists(int numThisYear, char[] talentCodes, string[] talentCodesStrings, string[] names, char[] talents, int[] counts) { int x; char QUIT = 'Z'; char option; bool isValid; int pos = 0; bool found; WriteLine(" The types of talent are:"); for (x = 0; x < counts.Length; ++x) WriteLine("{0, -20} {1, 5}", talentCodesStrings[x], counts[x]); Write(" Enter a talent type or {0} to quit >> ", QUIT); option = Convert.ToChar(ReadLine()); while (option != QUIT) { isValid = false; for (int z = 0; z < talentCodes.Length; ++z) { if (option == talentCodes[z]) { isValid = true; pos = z; } } if (!isValid) WriteLine("{0} is not a valid code", option); else { WriteLine(" Contestants with talent {0} are:", talentCodesStrings[pos]); found = false; for (x = 0; x < numThisYear; ++x) { if (talents[x] == option) { WriteLine(names[x]); found = true; } } if (!found) WriteLine("No contestants had talent {0}", talentCodesStrings[pos]); }

Write(" Enter a talent type or {0} to quit >> ", QUIT); option = Convert.ToChar(ReadLine()); } } }