What is Base64 Encoding?

Base64 encoding is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It is commonly used for encoding binary data, such as images or files, for transmission over text-based protocols like email or HTTP. The process involves converting groups of 8 bits into a single ASCII character, resulting in a more compact representation of binary data.

Decoding Base64 in C#:

In C#, to decode Base64 strings using the Convert class from the System namespace is simple. The FromBase64String method is used in this operation. 

using System;

class Program
{
    static void Main()
    {
        // Base64 encoded string
        string base64String = "SGVsbG8gV29ybGQh";

        // Decoding the Base64 string
        byte[] decodedBytes = Convert.FromBase64String(base64String);

        // Converting the decoded bytes to string
        string decodedString = System.Text.Encoding.UTF8.GetString(decodedBytes);

        // Displaying the original string
        Console.WriteLine("Decoded String: " + decodedString);
    }
}

We assigned the Base64-encoded string (SGVsbG8gV29ybGQh) to the variable and decode it into a byte array, and finally convert it back to a string using UTF-8 encoding. The output shows the decoding of the Base64 string into the original "Hello World!".

Output:

Decoded String: Hello World!