How to convert string to hex in C#

In C#, you can convert a string to its hexadecimal representation by encoding the string into bytes and then converting each byte to its hexadecimal form.

Using Encoding.UTF8.GetBytes(input) converts the input string to a byte array.

For example, c# string to hex

string StringToHex(string input)
{
    // Convert the string to bytes using UTF-8 encoding
    byte[] bytes = Encoding.UTF8.GetBytes(input);
    // Build the hexadecimal representation
    StringBuilder sb = new StringBuilder(bytes.Length * 2);
    // c# hex
    foreach (byte b in bytes)
        sb.AppendFormat("{0:X2}", b); // Uppercase hex
    return sb.ToString();
}

Use a StringBuilder to efficiently build the hex string, then use b.ToString("X2") formats each byte as a 2-digit uppercase hexadecimal string. Use "x2" for lowercase hex.

C# string format hex

In C#, you can format a number as a hexadecimal string using the ToString() method with a format specifier.

int number = 255;
string hex = number.ToString("X"); // Converts to uppercase hex, "FF"
string hexLower = number.ToString("x"); // Converts to lowercase hex, "ff"

Console.WriteLine(hex);      // Output: FF
Console.WriteLine(hexLower); // Output: ff

If you want to format a string with a specific width or padding, you can do that too:

int number = 255;
string paddedHex = number.ToString("X4"); // Ensures 4 hex digits, "00FF"
Console.WriteLine(paddedHex);  // Output: 00FF

You can also format other types like long, byte, etc., in a similar way.

C# parse hex string

To parse a hexadecimal string into a number in C#, you can use Convert.ToInt32() or int.Parse() with the "X" or "x" format specifier.

For example, Using Convert.ToInt32():

string hexString = "FF"; // Hexadecimal string
int number = Convert.ToInt32(hexString, 16); // Base 16 for hex
Console.WriteLine(number); // Output: 255

For example, Using int.Parse():

string hexString = "FF"; // Hexadecimal string
int number = int.Parse(hexString, System.Globalization.NumberStyles.HexNumber); // Parse with hex number style
Console.WriteLine(number); // Output: 255

Both methods will convert the hex string "FF" into the integer 255. You can replace "FF" with any valid hexadecimal string.