Develop Reference

Can't append a list to an existing file

I have an existing .txt file that I would like to use to store my data, but when using this code I get an error at line 39 at switch case 1.
using System;
using System.Collections.Generic;
using System.IO;
class Program
{
public static List<Pw> Site = new List<Pw>();
static void Main(string[] args)
{
string file = #"C: \Users\james\Documents\DataFolder\Vault.txt";
string command = "";
while (command != "exit")
{
Console.Clear();
Console.WriteLine("Please enter a command: ");
command = Console.ReadLine().ToLower();
switch (command)
{
case "1":
AddPw();
File.AppendAllLines(file, Pw.Site);
break;
case "2":
if (File.Exists(file))
{
// Read all the content in one string
// and display the string
string str = File.ReadAllText(file);
Console.WriteLine(str);
}
break;
}
}
}
private static void AddPw()
{
Pw pw = new Pw();
Console.Write("Enter the Username/Email: ");
pw.Username = Console.ReadLine();
Console.Write("Enter Full Name: ");
pw.FullName = Console.ReadLine();
Console.Write("Enter Phone Number: ");
pw.PhoneNumber = Console.ReadLine();
Console.Write("Enter Your Password: ");
string password = Console.ReadLine();
pw.Password = password;
Site.Add(pw);
}
private static void PrintPw(Pw pw)
{
Console.WriteLine("Username/Email: " + pw.Username);
Console.WriteLine("Full Name: " + pw.FullName);
Console.WriteLine("Phone Number: " + pw.PhoneNumber);
Console.WriteLine("Password: " + pw.Password[0]);
Console.WriteLine("-------------------------------------------");
}
private static void ListPw()
{
if (Site.Count == 0)
{
Console.WriteLine("Your address book is empty. Press any key to continue.");
Console.ReadKey();
return;
}
Console.WriteLine("Here are the current people in your address book:\n");
foreach (var pw in Site)
{
PrintPw(pw);
}
Console.WriteLine("\nPress any key to continue.");
Console.ReadKey();
}
}
public class Pw
{
public string Username { get; set; }
public string FullName { get; set; }
public string PhoneNumber { get; set; }
public string Password { get; set; }
}

I have updated your existing function.
using this function you can add and append data in existing file.
private static void AddPw(string filePath)
{
try
{
Pw pw = new Pw();
if (!File.Exists(filePath))
{
using (System.IO.StreamWriter sw = new System.IO.StreamWriter(filePath))
{
Console.Write("Enter the Username/Email: ");
pw.Username = Console.ReadLine();
sw.WriteLine(pw.Username);
Console.Write("Enter Full Name: ");
pw.FullName = Console.ReadLine();
sw.WriteLine(pw.FullName);
Console.Write("Enter Phone Number: ");
pw.PhoneNumber = Console.ReadLine();
sw.WriteLine(pw.PhoneNumber);
Console.Write("Enter Your Password: ");
pw.Password = Console.ReadLine();
sw.WriteLine(pw.Password);
}
}
else
{
using (StreamWriter sw = File.AppendText(filePath))
{
Console.Write("Enter the Username/Email: ");
pw.Username = Console.ReadLine();
sw.WriteLine(pw.Username);
Console.Write("Enter Full Name: ");
pw.FullName = Console.ReadLine();
sw.WriteLine(pw.FullName);
Console.Write("Enter Phone Number: ");
pw.PhoneNumber = Console.ReadLine();
sw.WriteLine(pw.PhoneNumber);
Console.Write("Enter Your Password: ");
pw.Password = Console.ReadLine();
sw.WriteLine(pw.Password);
}
}
}
catch (Exception ex)
{
}
}

File.AppendAllLines(file, Pw.Site);
In this line, you need to pass an IEnumerable for AppendAllLines to work. You can easily convert Site (which is List<Pw>) to an IEnumerable<string> using the ConvertAll method. Here's one way of achieving this:
Replace that line with this:
File.AppendAllLines(file, Site.ConvertAll<string>(
(p) => string.Format("{0} | {1} | {2} | {3}\n",
p.Username,
p.FullName,
p.PhoneNumber,
p.Password
))
);
This "lambda" basically takes your Pw object and converts it into a string inline.

how to make this bool in my c# program work

I'm new to programming, basically, as you will be able to see everything works up until I want to ask if the details are correct, whatever I type in it will always take the details as correct, I want to be able to type yes or no to the confirmation. I would really appreciate someone explain this to me so i can use bools properly
namespace UserFeedBack.cs
{
class MainClass
{
static void Main(string[] args)
{
Console.Write("Enter your name : ");
string Name = Console.ReadLine();
Console.WriteLine("Hey there, " +Name );
Console.ReadLine();
Console.Write("How old are you : ");
string Age = Console.ReadLine();
Console.WriteLine(" Hello " + Name + " you are " + Age + "!");
Console.Write("bank card account number :");
string AccountNumber = Console.ReadLine();
Console.WriteLine("Thank you! to confirm, is your account number : " + AccountNumber);
Console.ReadLine();
bool y = true;
if (y)
{
Console.WriteLine("Thank you, we can confirm your details are correct");
}
else
{
Console.WriteLine("re enter your details : ");
}
Console.ReadLine();
}
}
}

You've declared your bool property bool y = true;, and doing that sets the value of the bool to be always true. what you need to do is evaluate what the user is typing with Console.ReadLine(). If the user type "Yes" then you change the property to true, else you change it to false, like this:
class MainClass
{
static void Main(string[] args)
{
Console.Write("Enter your name : ");
string Name = Console.ReadLine();
Console.WriteLine("Hey there, " +Name );
Console.ReadLine();
Console.Write("How old are you : ");
string Age = Console.ReadLine();
Console.WriteLine(" Hello " + Name + " you are " + Age + "!");
Console.Write("bank card account number :");
string AccountNumber = Console.ReadLine();
Console.WriteLine("Thank you! to confirm, is your account number : " + AccountNumber);
bool confirmed = Console.ReadLine().ToLower() == "yes";
if (confirmed)
{
Console.WriteLine("Thank you, we can confirm your details are correct");
}
else
{
Console.WriteLine("re enter your details : ");
}
Console.ReadLine();
}
}

Password console application with the use of a while loop

So basically I'm trying to write a console application where it asks the user for a password and will continue to ask for it only three times and then stop with the use of a 'while' loop, but it keeps on looping and asking me for the password even if the correct password was used and after I entered it more that 3 times.
const string pass = "Password";
string attempt;
do
{
Console.Write("Please enter password: ");
attempt = Console.ReadLine();
if (attempt == pass)
{
Console.WriteLine("Access granted.");
}
else
{
Console.WriteLine("Access denied.");
}
} while (true);

const string pass = "Password";
string attempt;
int n = 0;
do
{
Console.Write("Please enter password: ");
attempt = Console.ReadLine();
if (attempt == pass)
{
Console.WriteLine("Access granted.");
break;
}
else
{
Console.WriteLine("Access denied.");
n++;
}
} while (n<=3);

So you want to ask user password three time until correct one entered and stop asking if user enter correct on. You can do it by for loop
const string pass = "Password";
string attempt;
for(int i=0;i<3;i++)
{
Console.Write("Please enter password: ");
attempt = Console.ReadLine();
if (attempt == pass)
{
Console.WriteLine("Access granted.");
i = 4;
}
else
{
Console.WriteLine("Access denied.");
}
};

You can do the following:
const string pass = "Password";
string attempt;
int attempt = 0;
do
{
Console.Write("Please enter password: ");
attempt = Console.ReadLine();
if (attempt == pass)
{
Console.WriteLine("Access granted.");
}
else
{
Console.WriteLine("Access denied.");
attempt++;
}
} while (attempt <= 3 && attempt != pass);

string pass = "";
while (pass != "password")
{
Console.WriteLine("enter your password here");
pass = Convert.ToString(Console.ReadLine());
if (pass == "password")
{
Console.WriteLine("your password is correct");
}
}
Console.ReadKey();

C# Visual Studio - Implementing user authentication using text files

Using visual studio 2013 and Console Application.
My question, How to I make something like this: I have a programm. I want the programm to check if there is a file called Usernames.txt, If there is,do nothing and if there is not, Create a new one.
Now when that Is done, I want the console to ask the person to enter a username, When the person does it, I want the programm to check if the file called: Usernames.txt contains that same username that the person entered, If yes, Then tell the person: This username already exists, Pick a new one. If not then add it to the file and continue on to ask for a password and so on.
This is what I got so far and I don't know what to do next:
Console.WriteLine("Username: ");
string uCreation = Console.ReadLine();
bool exists = false;
foreach (string lines in File.ReadAllLines("Usernames.txt"))
{
if (lines == uCreation)
{
Console.WriteLine("Username already exists!");
exists = true;
break;
}
}
if (!exists)
{
File.AppendAllText(#"Usernames.txt", uCreation + Environment.NewLine);
}
Am I on the right track? I have no idea D= If anybody could help out with some solutions that would be sweet!
Thanks!

You should be able to modify this code to suit your requirements.
class Program
{
static void Main(string[] args)
{
try
{
if (File.Exists(#"c:\Usernames.txt"))
{
Console.WriteLine("File already exists.I am doing nothing.Tadaaaaaaaaaa !!!");
return;
}
else
{
string sContinue = "yes";
HashSet<string> sUserNames = new HashSet<string>();
while (sContinue.Equals("yes"))
{
Console.WriteLine("Enter username:");
string sUserName = Console.ReadLine();
if (!sUserNames.Contains(sUserName))
{
sUserNames.Add(sUserName);
using (StreamWriter oWriter = new StreamWriter(#"c:\Usernames.txt", true))
oWriter.WriteLine(sUserName);
Console.WriteLine("Username {0} was added.Enter yes to continue or no to exit", sUserName);
}
else
Console.WriteLine("Username {0} exists.Enter yes to add new username or no to exit", sUserName);
sContinue = Console.ReadLine();
}
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
Console.WriteLine("Done");
Console.Read();
}
}

Here is your solution :
static void Main()
{
string path = #"C:\Usernames.txt";
if (File.Exists(path))
Console.WriteLine("File already exists. Exiting the application...");
else
{
List<string> list = new List<string>();
string IsContinue = "Y";
while (IsContinue.Equals("Y"))
{
Console.WriteLine("Enter the username --");
string userName = Console.ReadLine();
if (!list.Contains(userName))
{
list.Add(userName);
File.AppendAllText(path, userName + Environment.NewLine);
Console.WriteLine("Success...! Continue (Y/N) ?", userName);
IsContinue = Console.ReadLine().ToUpper();
}
else
Console.WriteLine("{0} already exists. Choose a new Username again.\n", userName);
}
}
}
....................................

How to know what user starts program?

I write simple program, that starts another Client.exe from user:
Console.Write("Enter your domain: ");
string domain = Console.ReadLine();
Console.Write("Enter you user name: ");
string uname = Console.ReadLine();
Console.Write("Enter your password: ");
SecureString password = new SecureString();
ConsoleKeyInfo key;
do
{
key = Console.ReadKey(true);
// Ignore any key out of range.
if (((int)key.Key) >= 33 && ((int)key.Key <= 90) && key.Key != ConsoleKey.Enter)
{
// Append the character to the password.
password.AppendChar(key.KeyChar);
Console.Write("*");
}
// Exit if Enter key is pressed.
} while (key.Key != ConsoleKey.Enter);
Console.WriteLine();
try
{
Console.WriteLine("\nTrying to launch ProcessClient using your login information...");
Process.Start("ProcessClient.exe", uname, password, domain);
}
catch (Win32Exception ex)
{
Console.WriteLine(ex.Message);
}
And it works! But how Client.exe knows what user execute this program?

You can know this using the Environment class:
Environment.UserName
Gets the user name of the person who is currently logged on to the Windows operating system.
Environment.UserDomainName
Gets the network domain name associated with the current user.