mechron mechron - 3 months ago 43
C# Question

Error: Help D: System.IO.IOException: The process cannot access the file because it is being used by another process

Code here ._.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
class Program
{

static void Main(string[] args)
{
System.IO.StreamWriter file = new System.IO.StreamWriter("C:\\Users\\Public\\Usernames.txt");
file.WriteLine();
file.Close();
int userType = 0;
System.IO.StreamReader fileUsername =
new System.IO.StreamReader("C:\\Users\\Public\\Usernames.txt");
file.Close();
string retrievedUsername = fileUsername.ReadToEnd();
file.Close();



Console.WriteLine("Please note that this is a prototype, passwords are not hashed/encrypted ^_^");
Console.WriteLine("Welcome to the meData service! Ver. 0.01 Beta, made by mechron");
Console.WriteLine("Please enter your username below or type register to register a new account on this device");
string loginUsername = Console.ReadLine();
if (loginUsername == retrievedUsername)
{

Console.WriteLine("Welcome back user!");
userType = 1;
}
else
{
if (loginUsername == "register")
{

Console.WriteLine("Choose your username!");
string registeredUsername = Console.ReadLine();
System.IO.StreamWriter files = new System.IO.StreamWriter("C:\\Users\\Public\\Usernames.txt");
file.WriteLine(registeredUsername);
file.Close();
}
else
{
Console.WriteLine("Error, command not recognized");}

}


}


}
}


My code above ^^ Erm... well... I'm having trouble with this.... System.IO.IOException: The process cannot access the file because it is being used by another process keeps popping up when I hit this line System.IO.StreamWriter files = new System.IO.StreamWriter("C:\Users\Public\Usernames.txt");
;
;
Can someone help me? Thanks in advance!

Answer

The following code does not close the reader - it closes the writer again. Even if it worked it would close the reader before you actually read.

System.IO.StreamReader fileUsername = new System.IO.StreamReader("C:\\Users\\Public\\Usernames.txt");
file.Close();
string retrievedUsername = fileUsername.ReadToEnd();
file.Close();

You should make your code look like this:

using (System.IO.StreamWriter file = new System.IO.StreamWriter("C:\\Users\\Public\\Usernames.txt"))
{
    file.WriteLine();
}

int userType = 0;
string retrievedUsername = String.Empty;

using (System.IO.StreamReader fileUsername = new System.IO.StreamReader("C:\\Users\\Public\\Usernames.txt"))
{
    retrievedUsername = fileUsername.ReadToEnd();
}

The code that follows is also flawed:

System.IO.StreamWriter files = new System.IO.StreamWriter("C:\\Users\\Public\\Usernames.txt");
file.WriteLine(registeredUsername);
file.Close();

See the error? You're opening (and not closing!!) a StreamWriter called files, but you're trying to write and trying to close file. Big mistake.

This can also be fixed like this:

using (System.IO.StreamWriter files = new System.IO.StreamWriter("C:\\Users\\Public\\Usernames.txt"))
{
    files.WriteLine(registeredUsername);
}