Microsoft Visual C# 7th edition.  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. Cengage requirement for the shaded part is attached and I don't understand it. I need help with the highlighted part (getContestantData() method) please. Thanks

 Microsoft Visual C# 7th edition.  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.

Cengage requirement for the shaded part is attached and I don't understand it. I need help with the highlighted part (getContestantData() method) please. Thanks

using System; 

using static System.Console;

using System.Globalization;

class GreenvilleRevenue

{

   static void Main()

 {

  int numLastYear;

     int numThisYear;

     double revenue;

     int fee = 25;

     const int MAX_CONTESTANTS = 30;

     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", 0, 30);

numThisYear = getContestantNumber("this", 0, 30);

WriteLine("Last year's competition had {0} contestants, and this year's has {1} contestants", numLastYear, numThisYear);

 revenue = (numThisYear * fee);

WriteLine("Revenue expected this year is {0}", revenue.ToString("C", CultureInfo.GetCultureInfo("en-US")));

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)

{

 int contestants;

 string contestantString;

 WriteLine("Enter number of contestants {0} year >> ", when);

 contestantString = ReadLine();

 while(! int.TryParse(contestantString, out contestants))

{

WriteLine("Invalid");

WriteLine("Reenter the valid constestants number");

contestantString = ReadLine();

}     

return contestants;

}

public static void DisplayRelationship( int numThisYear2, int numLastYear2)

{ if (numThisYear2 > 2 * numLastYear2)

WriteLine("The competition is more than twice as big this year!");

else

 if (numThisYear2 > numLastYear2)

 WriteLine("The competition is bigger than ever!");

 else

 if (numThisYear2 < numLastYear2)

 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;

string talentString;

while (x < numThisYear)

{ Write("Enter contestant name >> ");

names[x] = Console.ReadLine();

WriteLine("Talent codes are:");

for (int y = 0; y < talentCodes.Length; ++y)

WriteLine(" {0} {1}", talentCodes[y], talentCodesStrings[y]);

Write(" Enter talent code >> ");

talentString = ReadLine();

while(! char.TryParse(talentString, out talents[x]))

{ WriteLine(" Invalid format - entry must be a single character");

WriteLine("That is not a valid code");

Write(" Enter talent code >> ");

talentString = ReadLine();}

talents[x] = GetChar();

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] = GetChar();

}

}

++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("\nThe types of talent are:");

for (x = 0; x < counts.Length; ++x)

WriteLine("{0, -20} {1, 5}", talentCodesStrings[x], counts[x]);

WriteLine("\nEnter a talent type or {0} to quit >> ", QUIT);

option = GetChar();

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("\nContestants 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)

Console.WriteLine("No contestants had talent {0}",     talentCodesStrings[pos]);

}

WriteLine("\nEnter a talent type or {0} to quit >> ", QUIT);

 option = GetChar();

}

}

private static char GetChar()

 {char validChar = '0';

bool isValidChar = false;

var charInput = string.Empty;

 while (!isValidChar)

{ charInput = Console.ReadLine();

 isValidChar = Char.TryParse(charInput, out validChar);

 if (!isValidChar)

 {

WriteLine("Invalid character - Please try again by entering one character!");

               /* WriteLine("Invalid format - entry must be a single character");

 }

                else

WriteLine("That is not a valid code");*/

}

}

return validChar;-

}

}