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using methods for program?

So I did this hangman game, and it works perfectly fine, the only problem is that I want to use methods to organize everything.
And yes, it is a school project. I tried my best but whenever I try to put a part of the program in a method it's as if I removed a variable and it underlines it in red.
I removed them for now so it's more clear. also, the file I used contained 19 8 letters max words, one on each line.
Can someone tell me how I can incorporate methods without ruining the whole thing? also English isn't my first language plz excuse any mistakes, the code was in french and I translated it for this question. thank you very much. I appreciate your time and effort :)
using System;
using System.IO;
namespace TP3
{
class Program
{
public const String Dico = "dico.txt";
public static void Welcome()
{
//Mot de bienvenue
Console.WriteLine("Welcome to hangman !");
}
public static void Goodbye()
{
Console.WriteLine("thx for playing, goodbye!");
}
public static void Program()
{
int SolvedWords= 0;
string WordToGuess= "";
int NumberOfLetters ;
int x = 0;
int WordTried = 0;
Console.WriteLine("");
Console.WriteLine("Do you wanna guess a word ? oui or non.");
Console.WriteLine("you have 8 chances per word.");
string Answer= Console.ReadLine();
Answer= Answer.ToLower();
while (Answer== "oui" && WordTried <19)
{
const int Lives= 8;
int LostLives= 0;
int LivesLeft= 8;
int LettersGuesed= 0;
x += 1;
WordTried += 1;
if (WordTried <= 20 && WordTried >1)
{
Console.WriteLine("Do you wanna guess a word ? oui or non.");
Answer= Console.ReadLine();
Answer= Answer.ToLower();
}
//Read a word in the file
int compteur = 0;
string ligne;
// Read file and show on the line
System.IO.StreamReader file = new System.IO.StreamReader(#"dico.txt");
while ((line = file.ReadLine()) != null)
{
compteur++;
if (compteur == x)
{
WordToGuess= line;
}
}
file.Close();
char[] table;
table = new char[WordToGuess.Length];
for (int i = 0; i < table.Length; i++)
{
table[i] = WordToGuess [i];
}
//change each letter into a *
Console.WriteLine("here’s the word to guess : ");
string HiddenWord = "********";
char[] table2;
table2 = new char[WordToGuess.Length];
for (int i = 0; i < table2.Length; i++)
{
table2[i] = HiddenWord[i];
}
for (int i = 0; i < table2.Length; i++)
{
Console.Write(table2[i]);
}
Console.WriteLine("");
//guess the word
while (LettersGuesed< WordToGuess.Length && LivesLeft> 0)
{
Console.WriteLine("");
/* Console.WriteLine("Devinez une seule Letterdu mot. Ne pas écrire une Letter plus d'une fois de suite. Si c'est le cas, recommencez le jeu.");*/
string Letter= Console.ReadLine();
Letter= Letter.ToLower();
NumberOfLetters = Letter.Length;
char[] table3;
table3= new char[NumberOfLetters ];
for (int i = 0; i < table2.Length; i++)
{
if (table[i].Equals(Letter[0]))
{
Table2[i] = Letter[0];
LettersGuesed+= 1;
}
}
for (int i = 0; i < table2.Length; i++)
{
Console.Write(table2[i]);
}
if (WordToGuess.IndexOf(Lettre) < 0)
{
Console.WriteLine("");
Console.WriteLine("wrong letter.");
LostLives+= 1;
LivesLeft= Lives- LostLives;
Console.WriteLine("you have " + LivesLeft+ " lives left.");
}
if (WordToGuess.IndexOf(Lettre) >= 0)
{
Console.WriteLine(" ");
Console.WriteLine("right !");
Console.WriteLine("you have " + LivesLeft+ " lives left.");
}
if (LettersGuesed== WordToGuess.Length && LivesLeft> 0)
{
SolvedWords+= 1;
Console.WriteLine(" ");
Console.WriteLine("you found the word !");
Console.WriteLine("you found " + SolvedWords+ " on" + WordTried + " words so far.");
}
if (LivesLeft== 0)
{
Console.WriteLine("you couldnt guess the word.");
Console.WriteLine("the word was :");
for (int i = 0; i < table.Length; i++)
{
Console.Write(table[i]);
}
Console.WriteLine(" ");
Console.WriteLine("you found " + SolvedWords+ " on" + WordTried + " words so far.");
}
if (WordTried == 19)
{
Console.WriteLine("no more words to guess.");
}
}
}
}
static void Main(string[] args)
{
Welcome();
Programme();
Goodbye();
}
}
}

Im not going to make every method for your project, I'll help kickstart on how to think about it. Look at your current code for reading the file of words. You can move that into a method -
public string[] ReadWordsFromFile()
{
string file = "path to your file here";
return File.ReadAllLines(file);
}
Or pass the file path as parameter -
public string[] ReadWordsFromFile(string filePath)
{
return File.ReadAllLines(filePath);
}
Next you can have a method to get random words -
public string GetRandomWord(string[] wordsArray)
{
Random random = new Random();
int randomIndex = random.Next(0, wordsArray.Length);
return wordsArray[randomIndex];
}
Note - words can be repeated if you do it this way, if you don't want that - then add logic to remove that item from the list once its used in the game. If you remove it within this method, its not actually going to remove it from the game, as you'll still be passing the entire array when getting a new word. Ill leave the implementation of that logic to you, if you want it.
In the "game controller" code -
you can use the above methods like this -
string file = "your path to txt file";
string[] allWords = ReadWordsFromFile(file);
string WordToGuess = GetRandomWord(allWords);
May be your next goal should be something like this -
public void GameControler()
{
// get all words here and other logic before game starts
while (Attempts > 0)
{
string WordToGuess = GetRandomWord(wordsArray);
// get letterGuessed from user
bool letterExists = CheckIfLetterExists(WordToGuess, letterGuessed);
if (!letterExists)
{
Attempts--;
ExecuteWrongGuessMethod(x, y);
}
else
{
ExecuteRightGuessMethod(w);
}
}
}
public bool CheckIfLetterExists(string word, string letter)
{
if (word.Contains(letter)) return true;
else return false;
}
public void ExecuteWrongGuessMethod(string passWhatYouNeedTo, int somethingElse)
{
// what to do when the guess is wrong e.g. Console.Writeline("wrong guess");
}
public void ExecuteRightGuessMethod(string word)
{
// logic when guess is right. e.g. Show the letter guessed within the word on the console etc.
}
All of this isn't the best way to do it. BUT I personally feel this is logically next step a beginner takes after what you've implemented. Seeing a fully well-developed program might be too much without understanding atleast some basic concepts of OOP.
After learning how to create Methods and use them, then comes classes and objects. Which should be implemented in this game, but this is all for now. I recommend you do a short C# course on coursera etc or even youtube. And slowly move towards a better understanding of SOLID principles. And by SOLID I mean an acronym for the 5 principles and not the actual word. All the best.

How do I search an int array vs a string array by comparing it to user input

How do I check if user input matches a number in an array?
I've learned to compare user input or search using a string array, however doing the same with an int array is not working for me.
zipCode[i] = 0;
int userZip = 0;
do
{
Console.WriteLine( "enter a 5 digit zip code to see if it is supported in our area." );
Console.WriteLine( );
Console.WriteLine( "Enter a 0 to exit the program" );
userZip = 0;
if ( userZip == zipCode[i] )
{
found = true;
if ( found )
{
Console.WriteLine( "We support zip code {0}", userZip ); ;
}
else
{
Console.WriteLine( "We do not support", userZip );
}
}
} while ( userZip != 0 );
Console.ReadLine( );

How do I check if user input matches a number in an array?
using System;
using System.Collections.Generic;
public class Program
{
static List<string> _zipCodes;
static Program()
{
_zipCodes = new List<string>() { "80205", "80225", "80210" };
}
static void Main(string[] args)
{
string userZip = string.Empty;
do
{
Console.WriteLine("enter a 5 digit zip code to see if it is supported in our area.");
Console.WriteLine();
Console.WriteLine("Enter a -1 to exit the program");
userZip = Console.ReadLine();
if (_zipCodes.Contains(userZip))//<---------------THAT WAY
{
Console.WriteLine("We support zip code {0}", userZip); ;
}
else
{
Console.WriteLine("We do not support zip code {0}", userZip);
}
} while (userZip != "-1");
}
}

How do I check if user input matches a number in an array?
I will answer this question, though I can't post an example using your sample code since it's incomplete and it's not exactly clear what it's supposed to do.
First, let's create a method that gets an integer from the user. This method will continually loop until the user enters a valid integer:
public static int GetIntFromUser(string prompt = null)
{
int input;
int row = Console.CursorTop;
int promptLength = prompt?.Length ?? 0;
do
{
Console.SetCursorPosition(0, row);
Console.Write(prompt + new string(' ', Console.WindowWidth - promptLength - 1));
Console.CursorLeft = promptLength;
} while (!int.TryParse(Console.ReadLine(), out input));
return input;
}
Now, we can use that method to get the zip code from the user:
int userZipCode = GetIntFromUser("Enter a 5 digit zip code to see if it's supported: ");
Now I'm assuming you have an array of zip codes that are supported. Perhaps something like:
private static int[] GetSeattleZipCodes()
{
return new []
{
98101, 98102, 98103, 98104, 98105, 98106, 98107, 98108, 98109, 98110,
98111, 98112, 98113, 98114, 98115, 98116, 98117, 98118, 98119, 98121,
98122, 98124, 98125, 98126, 98127, 98129, 98131, 98133, 98134, 98136,
98138, 98139, 98141, 98144, 98145, 98146, 98148, 98154, 98155, 98158,
98160, 98161, 98164, 98165, 98166, 98168, 98170, 98174, 98175, 98177,
98178, 98181, 98185, 98188, 98190, 98191, 98194, 98195, 98198, 98199
};
}
So, now we have an int user input, and an int[] of valid zip codes, so to see if the array of valid zip codes contains the user zip code, we can just use the Contains method:
int[] seattleZipCodes = GetSeattleZipCodes();
bool found = seattleZipCodes.Contains(userZipCode);

TheFastCat beat me, but:
using System;
using System.Collections.Generic;
namespace ConsoleApplication1
{
class Program
{
private static IEnumerable<string> zipCodes = new string[] { "90210", "94102", "98101", "80014" };
static void Main(string[] args)
{
Console.WriteLine("enter a 5 digit zip code to see if it is supported in our area, or '0' to exit");
do {
// Read next line
string userZip = Console.ReadLine().Trim();
// Exit program?
if (userZip == "0")
break;
// Validate input
if (userZip.Length != 5)
{
Console.WriteLine("ERROR: Zip code {0} is {1} characters; expected 5", userZip, userZip.Length);
continue;
}
int n;
bool isNumeric = int.TryParse(userZip, out n);
if (!isNumeric)
{
Console.WriteLine("ERROR: Zip code {0} must be numeric", userZip);
continue;
}
// Finally, see if our zip code matches a zip code in the list
bool found = zipCodes.Contains(userZip);
if (found)
{
Console.WriteLine("We support zip code {0}", userZip); ;
}
else
{
Console.WriteLine("We do not support " + userZip);
}
} while (true);
Console.WriteLine("Done: exiting program");
}
}
}
Note:
Initializing the list
Validating the input
Using IEnumerable.Contains() ... without necessarily messing with LINQ.
Use of "break" and "continue" to control the loop, without necessarily needing an extraneous variable.

An int array is Enumerable<int>, so you could just use Contains(): https://learn.microsoft.com/en-us/dotnet/api/system.linq.enumerable.contains?view=netframework-4.7.2

TheFastCat and Rufus L done great job.
I just want to add an example. Using 'var' datatypes makes things easy and durable as well in C#
This example demonstrates both 'int' and 'string' using var datatypes in both cases. Good luck haberjin.
static void Main(string[] args)
{
//var ZipCodes = new List<string>() { "04846", "40569", "76859","54896", "84623" }; // ZipCodes are stored as a string in a List
var ZipCodes = new List<int>() { 04846, 40569, 76859, 54896, 84623 }; // ZipCodes are stored as an int in a List
//var userZip = "";
var userZip = 0;
do
{
Console.WriteLine("Enter a 5 digit zip code to see if it is supported in our area.");
//userZip = Console.ReadLine(); // Enable to receive userZip as a string
userZip = int.Parse(Console.ReadLine()); // receive userZip as an int
if (ZipCodes.Contains(userZip))
{
Console.WriteLine("We support zip code {0}", userZip);
}
else
{
Console.WriteLine("We do not support", userZip);
}
//} while (userZip != "0");
} while (userZip != 0);
}

Is there any way to save char Array in For loop?

I want to create a simple hangman and I'm stuck :/.
Here is simple code what detects all chars in the array.
I need some way to save it and then write it.
I add the comment in the code for more readability and where I want to save.
And at the end i need to write it.
Is there anything I could do better in code? I'm a newbie.
public static void Main(string[] args)
{
char[] array;
randomWord = "apple".ToCharArray();
Console.WriteLine(randomWord);
while (guessing == true) {
Console.WriteLine();
userinput = char.Parse(Console.ReadLine());
for (int i = 0; i < randomWord.Length; i++)
{
if (randomWord[i].ToString().Contains(userinput))
{
Console.Write(userinput);
//add to array
enter code here
}
else
{
//add to array
enter code here
Console.Write("_ ");
}
}
//and here Write whole array
for(int g = 0; g < array.Lenght; g++){
Console.Write(array[g]);
}
}

Use a generic list (List<T>) they are more flexible than arrays:
public static void Main(string[] args)
{
List<char> array = new List<char>();
randomWord = "apple".ToCharArray();
Console.WriteLine(randomWord);
while (guessing == true) {
Console.WriteLine();
userinput = char.Parse(Console.ReadLine());
for (int i = 0; i < randomWord.Length; i++)
{
if (randomWord[i].ToString().Contains(userinput))
{
Console.Write(userinput);
//add to array
array.Add(randomWord[i]);
}
else
{
//it's not clear what you want to add to here?
Console.Write("_ ");
}
}
//and here Write whole array
//use a foreach
foreach(char c in array ){
Console.Write(c);
}
//your missing a brace
}
}

c# : string length without predefined function

I am writing a code to find out the total length of string in c#.
code is as follow
class Program
{
static void Main(string[] args)
{
string str = "Amit Kumar";
int c = 0;
for(int i = 0; str[i]!="\n"; i++)
{
c++;
}
Console.WriteLine(c);
Console.ReadLine();
}
}
but it showing != operator can not be applied to operands on char or string type.
can you solve my problem

You can't compare a string to a char using != as stated in the error. So use '\n' instead. But anyways, your string doesn't contain the newline character and would never terminate.
We can make your code work with some modifications. Use foreach to loop over the characters in the string.
class Program
{
static void Main(string[] args)
{
string str = "Amit Kumar";
int c = 0;
foreach(char x in str)
{
c++;
}
Console.WriteLine(c);
Console.ReadLine();
}
}
I hope this is just for education, as there's built in functions to tell you the length of a string.

You need this code:
class Program
{
static void Main(string[] args)
{
string str = "Amit Kumar";
int c = 0;
foreach(char x in str)
{
if (str[i] != '\n')
c++;
}
Console.WriteLine(c);
Console.ReadLine();
}
}

mason's answer is perfectly fine, but here's an alternative:
void Main()
{
string str = "Amit Kumar";
int c = 0;
while(str != "")
{
str = str.Substring(1);
c++;
}
Console.WriteLine(c);
Console.ReadLine();
}
This method successively removes characters until it's left with the empty string, then prints the number of characters removed. But just for fun, this can be rewritten as
void Main()
{
string str = "Amit Kumar";
int c = 0;
while(str.Substring(++c) != "") /* do nothing */;
Console.WriteLine(c);
Console.ReadLine();
}

Error 1 Cannot implicitly convert type 'int**' to 'int*'. An explicit conversion exists (are you missing a cast?)

I'm learning C and C# and this question is for C#. I looking at pointers at msdn and this code is not compiling, it gives the error:Error 1 Cannot implicitly convert type int** to int*. An explicit conversion exists (are you missing a cast?). What am I missing here?
Here is the code:
int ix = 10;
unsafe
{
int* px1;
int* px2 = &ix; **The error is on this line**
}
EDIT:
Here is the program in its entirety:
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Management;
using System.Diagnostics;
using System.Windows.Forms;
using practice;
class Program
{
public delegate bool ThisIsTheDelegate(int number);
public delegate bool ThisIsAnotherDelegate(int number);
private static string address;
public static String Address
{
get
{
return address;
}
set
{
address = value;
}
}
static void Main()
{
int[] someArray = new int[] { 1, 2, 3, 5, 6, 7, 8, 9, 0 };
foreach (int number in someArray)
{
Console.WriteLine(number);
}
int integer = 98;
string someString = "edited";
string[] someStr = { "edited" };
String[] anotherStringSomestr = new String[] { "edited" };
var readWithLinq = from far in anotherStringSomestr
select far;
foreach (var some in readWithLinq)
{
Console.WriteLine(some);
}
Program newPro = new Program();
bool isEven1 = newPro.isEven(99);
Console.WriteLine(isEven1);
ThisIsTheDelegate newDelegate = newPro.isEven;
Console.WriteLine(newDelegate(98));
int[] numbers = { 1, 2, 3, 5, 6, 7, 8, 9 };
List<int> evenNumbers = FilterArray(numbers, newDelegate);
foreach(int integer1 in evenNumbers)
{
Console.WriteLine(integer1);
}
List<int> oddNumbers = FilterArray(numbers, isOdd);
foreach (int integer1 in oddNumbers)
{
Console.WriteLine(integer1);
}
ThisIsAnotherDelegate anotherDelegate;
anotherDelegate = number => (number % 2 == 0);
Console.WriteLine("{0} is a even number", anotherDelegate(4));
for (int i = 0; i < someString.Length; i++)
{
Console.WriteLine(someString);
}
for (int i = 0; i < someStr.Length; i++)
{
Console.WriteLine(someStr[i]);
}
Console.WriteLine(integer);
SimpleStruct structss = new SimpleStruct();
structss.DisplayX();
M.x = 1;
structss.x = 98;
Console.WriteLine(M.x);
Console.WriteLine(structss.x);
M.structtaker(ref structss);
M.classtaker();
Console.WriteLine(structss.x);
Console.WriteLine(M.x);
M.x = 1;
structss.x = 98;
int ix = 10;
unsafe
{
int* px1;
int* px2 = &ix;
}
int selection = 98;
while (selection != 0)
{
mainMenu();
Console.Write("Enter choice: ");
selection = Convert.ToInt32(Console.ReadLine());
switch (selection)
{
case 0:
break;
case 1:
openSomething();
break;
case 2:
calculator();
break;
case 3:
coolestProgramEverALive();
break;
case 4:
make_to_do_list();
break;
case 5:
add_to_do_list();
break;
case 6:
readToDoList();
break;
case 7:
linq_and_arrays();
break;
case 8:
calendar();
break;
case 9:
linq_and_collections();
break;
default:
Console.WriteLine("Unkown selection. Try again");
break;
}
}
}
private static bool isOdd(int number)
{
return (number % 2 == 1);
}
private static List<int> FilterArray(int[] numbers, ThisIsTheDelegate newDelegate)
{
List<int> result = new List<int>();
foreach (int item in numbers)
{
if (newDelegate(item))
result.Add(item);
}
return result;
}
private static void linq_and_collections()
{
List<string> names = new List<string>();
names.Add("Billy");
names.Add("Steve");
names.Add("Casandra");
names.Insert(0, "Johanna");
names.Add("Sonny");
names.Add("Suzanne");
names.Insert(2, "Sid");
var queryLinqUpper = from name in names
where (name.StartsWith("S") || name.StartsWith("B") || name.StartsWith("J"))
let namesToUpper = name.ToUpper()
orderby namesToUpper
select namesToUpper;
foreach (var linqToUpper in queryLinqUpper)
{
Console.Write(linqToUpper + " ");
}
Console.WriteLine();
M.WriteTextToConsole("Hello, world. Programming in C# is fun");
char c = 'A';
int count = 14;
String str = new String(c, count);
str.WriteTextToConsole();
M.WriteTextToConsole(str);
}
private static void calendar()
{
Application.Run(new Form1());
}
private static void readToDoList()
{
var files = from file in Directory.GetFiles(#"C:\data", "*.txt")
select file;
int number = 1;
foreach (var file in files)
{
Console.WriteLine(number + ". " + file);
number++;
}
Console.Write("What todolist do you want to read? Give me the name:");
try
{
string name = Console.ReadLine();
Address = Path.Combine(#"C:\data", name + ".txt");
TextReader inFile = new StreamReader(Address);
while (inFile.Peek() != -1)
{
string line = inFile.ReadLine();
Console.WriteLine(line);
}
inFile.Close();
}
catch (Exception ex)
{
MessageBox.Show("Exception thrown!", "Error");
Console.WriteLine(ex.ToString());
}
}
private static void linq_and_arrays()
{
int numberOfElements;
Console.WriteLine("Start by setting the int[] array.");
Console.Write("How many elements are there in your array?");
numberOfElements = Convert.ToInt32(Console.ReadLine());
int[] array = new int[numberOfElements];
for (int i = 0, j = numberOfElements; i < numberOfElements; i++, j--)
{
Console.Write("Integers left to add {0}. Enter an integer:", j);
array[i] = Convert.ToInt32(Console.ReadLine());
}
var arrayquery = from value in array
select value;
foreach (var val in arrayquery)
{
Console.WriteLine("Value from array:{0}", val);
}
}
private static void add_to_do_list()
{
Console.WriteLine("Which todolist do you want to modify?");
listToDoLists();
Console.Write("Enter name of todolist: ");
string name = Console.ReadLine();
Address = Path.Combine(#"C:\data", name + ".txt");
String tempString;
StreamWriter stream;
stream = File.AppendText(Address);
Console.Write("Enter your new ToDo: ");
tempString = Console.ReadLine();
stream.WriteLine(tempString);
stream.Close();
TextReader inFile;
inFile = new StreamReader(Address);
while (inFile.Peek() != -1)
{
string line = inFile.ReadLine();
Console.WriteLine(line);
}
inFile.Close();
}
private static void listToDoLists()
{
int filenumber = 1;
string[] filepaths = Directory.GetFiles("C:\\data\\", "*.txt");
foreach (string file in filepaths)
{
Console.WriteLine(filenumber + ". " + file);
filenumber++;
}
}
private static void make_to_do_list()
{
string path, name;
string yesOrNo;
Console.Write("Enter name of todolist: ");
name = Console.ReadLine();
path = Path.Combine(#"C:\data", name + ".txt");
TextWriter outFile = new StreamWriter(path);
labelOne: // else clause : unknown answer
Console.WriteLine("Do you want to add something to todolist.Y/N?");
yesOrNo = Console.ReadLine();
if (yesOrNo.ToLower() == "y")
{
string line;
int lines;
Console.Write("How many lines?");
lines = Convert.ToInt32(Console.ReadLine());
for (int i = 0; i < lines; i++)
{
Console.Write("Enter a line of text: ");
line = Console.ReadLine();
outFile.WriteLine(line);
}
outFile.Close();
}
else if (yesOrNo.ToLower() == "n")
{
Console.WriteLine("You can close the application now.");
}
else
{
Console.WriteLine("Unknown answer. Try again");
goto labelOne;
}
}
private static void coolestProgramEverALive()
{
System.Diagnostics.Process.Start(#"C:\Users\KristjanBEstur\Documents\Visual Studio 2012\Projects\The_coolest_program_ever_alive\The_coolest_program_ever_alive\obj\Debug\The_coolest_program_ever_alive.exe");
}
private static void calculator()
{
System.Diagnostics.Process.Start("calc");
}
private static void openSomething()
{
System.Diagnostics.Process.Start("notepad");
}
private static void mainMenu()
{
Console.WriteLine("Main Menu");
Console.WriteLine("0. Quit");
Console.WriteLine("1. OpenSomething");
Console.WriteLine("2. Calculator");
Console.WriteLine("3. coolestProgramEverAlive");
Console.WriteLine("4. Make todolist");
Console.WriteLine("5. Add to todolist");
Console.WriteLine("6. Read to do list");
Console.WriteLine("7. Linq and arrays");
Console.WriteLine("8. Calendar");
Console.WriteLine("9. Linq and collections");
}
public bool isEven(int number)
{
return (number % 2 == 0);
}
}
static class M
{
public static int x;
public static void WriteTextToConsole(this string text)
{
Console.WriteLine(text);
}
public static void structtaker(ref SimpleStruct s)
{
s.x = 5;
}
public static void classtaker()
{
M.x = 5;
}
}
class Test
{
static int value = 20;
unsafe static void F(out int* pi1, ref int* pi2) {
int i = 10;
pi1 = &i;
fixed (int* pj = &value) {
// ...
pi2 = pj;
}
}
}
struct SimpleStruct
{
public int x;
private int xval;
public int X
{
get
{
return xval;
}
set
{
if (value < 100)
xval = value;
}
}
public void DisplayX()
{
Console.WriteLine("The stored value is: {0}", X);
}
}

I wished I could replicate this it seems like a rather interesting issue. Here is the section of the standard that I believe applies to this (sorry about the formatting):
18.3 Fixed and moveable variables The address-of operator (§18.5.4) and the fixed statement (§18.6) divide variables into two categories:
Fixed variables and moveable variables. Fixed variables reside in
storage locations that are unaffected by operation of the garbage
collector. (Examples of fixed variables include local variables, value
parameters, and variables created by dereferencing pointers.) On the
other hand, moveable variables reside in storage locations that are
subject to relocation or disposal by the garbage collector. (Examples
of moveable variables include fields in objects and elements of
arrays.) The & operator (§18.5.4) permits the address of a fixed
variable to be obtained without restrictions. However, because a
moveable variable is subject to relocation or disposal by the garbage
collector, the address of a moveable variable can only be obtained
using a fixed statement (§18.6), and that address remains valid only
for the duration of that fixed statement. In precise terms, a fixed
variable is one of the following: • A variable resulting from a
simple-name (§7.6.2) that refers to a local variable or a value
parameter, unless the variable is captured by an anonymous function.
• A variable resulting from a member-access (§7.6.4) of the form V.I,
where V is a fixed variable of a struct-type. • A variable resulting
from a pointer-indirection-expression (§18.5.1) of the form *P, a
pointer-member-access (§18.5.2) of the form P->I, or a
pointer-element-access (§18.5.3) of the form P[E]. All other variables
are classified as moveable variables. Note that a static field is
classified as a moveable variable. Also note that a ref or out
parameter is classified as a moveable variable, even if the argument
given for the parameter is a fixed variable. Finally, note that a
variable produced by dereferencing a pointer is always classified as a
fixed variable.
I spend some time trying to create a similar error but wasn't about to. The only way I was able to recreate the issue was with the following code:
void test() {
int ix = 10;
unsafe {
int* px1 = &ix;
int* px2 = &px1; // **The error is on this line**
}
}
Of course this code cannot be fixed by moving the ix declaration into the safe scope. Perhaps you could try replicating the original problem in a very small bit of code (like above) and verify that both the problem and the fix replicate. Perhaps VS became confused. I have had problems that made no sense and went away by exiting VS and restarting (not often but a few times).

I moved the i declaration down inside the unsafe block and it fixed it, I don't know why?
Here is the code:
unsafe
{
int ix = 10;
int* px1;
int* px2 = &ix;
}

I've moved the expression "int i = 10;" out of the unsafe block and now it compiles. I've also put the code in question in a new project of another instance of vs2012pro. And that also compiles. So now I'm unable to replicate the error.
Here is the code:
int ix = 10;
unsafe
{
int* px1;
int* px2 = &ix;
Test.F(out px1, ref px2);
Console.WriteLine("*px1 = {0}, *px2 = {1}",
*px1, *px2); // undefined behavior
}
Here is the other project:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace saxerium
{
class Program
{
static void Main(string[] args)
{
int ix = 10;
unsafe
{
int* px1;
int* px2 = &ix;
Test.F(out px1, ref px2);
Console.WriteLine("*px1 = {0}, *px2 = {1}",
*px1, *px2); // undefined behavior
}
}
}
class Test
{
static int value = 20;
public unsafe static void F(out int* pi1, ref int* pi2)
{
int i = 10;
pi1 = &i;
fixed (int* pj = &value)
{
// ...
pi2 = pj;
}
}
}
}