Storing passwords as plain text is dangerous. Instead, you should hash them using a strong, slow hashing algorithm like BCrypt, which includes built-in salting and resistance to brute-force attacks.
Step 1: Install BCrypt NuGet Package
Before using BCrypt, install the BCrypt.Net-Next package:
dotnet add package BCrypt.Net-Next
or via NuGet Package Manager:
Install-Package BCrypt.Net-Next
Step 2: Hash a Password
Use BCrypt.HashPassword() to securely hash a password before storing it:
using BCrypt.Net;
string password = "mySecurePassword123";
string hashedPassword = BCrypt.HashPassword(password);
Console.WriteLine(hashedPassword); // Output: $2a$12$...
Step 3: Verify a Password
To check a user's login attempt, use BCrypt.Verify():
bool isMatch = BCrypt.Verify("mySecurePassword123", hashedPassword);
Console.WriteLine(isMatch); // Output: True
Ensuring proper hashing should be at the top of your list when it comes to building authentication systems.
Reading a file line by line is useful when handling large files without loading everything into memory at once.
✅ Best Practice: Use File.ReadLines() which is more memory efficient.
Example
foreach (string line in File.ReadLines("file.txt"))
{
Console.WriteLine(line);
}
Why use ReadLines()?
Reads one line at a time, reducing overall memory usage.
Ideal for large files (e.g., logs, CSVs).
Alternative: Use StreamReader (More Control)
For scenarios where you need custom processing while reading the contents of the file:
using (StreamReader reader = new StreamReader("file.txt"))
{
string? line;
while ((line = reader.ReadLine()) != null)
{
Console.WriteLine(line);
}
}
Why use StreamReader?
Lets you handle exceptions, encoding, and buffering.
Supports custom processing (e.g., search for a keyword while reading).
When to Use ReadAllLines()?
If you need all lines at once, use:
string[] lines = File.ReadAllLines("file.txt");
Caution: Loads the entire file into memory—avoid for large files!
Closing a SqlDataReader correctly prevents memory leaks, connection issues, and unclosed resources. Here’s the best way to do it.
Use 'using' to Auto-Close
Using using statements ensures SqlDataReader and SqlConnection are closed even if an exception occurs.
Example
using (SqlConnection conn = new SqlConnection(connectionString))
{
conn.Open();
using (SqlCommand cmd = new SqlCommand("SELECT * FROM Users", conn))
using (SqlDataReader reader = cmd.ExecuteReader())
{
while (reader.Read())
{
Console.WriteLine(reader["Username"]);
}
} // ✅ Auto-closes reader here
} // ✅ Auto-closes connection here
This approach auto-closes resources when done and it is cleaner and less error-prone than manual closing.
⚡ Alternative: Manually Close in finally Block
If you need explicit control, you can manually close it inside a finally block.
SqlDataReader? reader = null;
try
{
using SqlConnection conn = new SqlConnection(connectionString);
conn.Open();
using SqlCommand cmd = new SqlCommand("SELECT * FROM Users", conn);
reader = cmd.ExecuteReader();
while (reader.Read())
{
Console.WriteLine(reader["Username"]);
}
}
finally
{
reader?.Close(); // ✅ Closes reader if it was opened
}
This is slightly more error prone if you forget to add a finally block. But might make sense when you need to handle the reader separately from the command or connection.