Base64 String in C#

To encode a string to base64 in C#, you can use the Convert.ToBase64String() method:

string originalString = "Hello, world!";
byte[] bytesToEncode = Encoding.UTF8.GetBytes(originalString);
string encodedString = Convert.ToBase64String(bytesToEncode);

To decode a base64 string in C#, you can use the Convert.FromBase64String() method:

string encodedString = "SGVsbG8sIHdvcmxkIQ==";
byte[] decodedBytes = Convert.FromBase64String(encodedString);
string decodedString = Encoding.UTF8.GetString(decodedBytes);

To convert a file to a base64 string in C#, you can read the file into a byte array using a FileStream, and then encode the byte array to a base64 string:

string filePath = "path/to/file";
byte[] fileBytes = File.ReadAllBytes(filePath);
string base64String = Convert.ToBase64String(fileBytes);

To decode a Java encoded base64 string in C#, you can use the Convert.FromBase64String() method and replace any dashes (-) with plus signs (+) and any underscores (_) with forward slashes (/):

string encodedString = "SGVsbG8sIHdvcmxkIQ==";
encodedString = encodedString.Replace('-', '+').Replace('_', '/');
byte[] decodedBytes = Convert.FromBase64String(encodedString);
string decodedString = Encoding.UTF8.GetString(decodedBytes);

To encode a FileStream to a base64 string in C#, you can read the stream into a byte array using a BinaryReader, and then encode the byte array to a base64 string:

using (FileStream stream = new FileStream("path/to/file", FileMode.Open))
using (BinaryReader reader = new BinaryReader(stream))
{
    byte[] bytes = reader.ReadBytes((int)stream.Length);
    string base64String = Convert.ToBase64String(bytes);
}

Convert string to Base64 in C#:

string originalString = "Hello, Base64!";
byte[] bytesToEncode = Encoding.UTF8.GetBytes(originalString);
string base64String = Convert.ToBase64String(bytesToEncode);
// Result: "SGVsbG8sIEJhc2U2NCE="

Base64 encoding in C# example:

byte[] bytesToEncode = Encoding.UTF8.GetBytes("Hello, Base64!");
string base64String = Convert.ToBase64String(bytesToEncode);
// Result: "SGVsbG8sIEJhc2U2NCE="

Decode Base64 string in C#:

string base64String = "SGVsbG8sIEJhc2U2NCE=";
byte[] decodedBytes = Convert.FromBase64String(base64String);
string decodedString = Encoding.UTF8.GetString(decodedBytes);
// Result: "Hello, Base64!"

C# Convert.ToBase64String method:

byte[] bytesToEncode = Encoding.UTF8.GetBytes("Hello, Base64!");
string base64String = Convert.ToBase64String(bytesToEncode);
// Result: "SGVsbG8sIEJhc2U2NCE="

Base64 encoding and decoding with MemoryStream in C#:

using (MemoryStream stream = new MemoryStream())
{
    // Write data to the stream
    // ...

    byte[] bytesToEncode = stream.ToArray();
    string base64String = Convert.ToBase64String(bytesToEncode);

    // Decode
    byte[] decodedBytes = Convert.FromBase64String(base64String);
    // ...
}

C# Convert.FromBase64String method:

string base64String = "SGVsbG8sIEJhc2U2NCE=";
byte[] decodedBytes = Convert.FromBase64String(base64String);
string decodedString = Encoding.UTF8.GetString(decodedBytes);
// Result: "Hello, Base64!"

Base64 URL encoding in C#:

string originalString = "Hello, Base64!";
byte[] bytesToEncode = Encoding.UTF8.GetBytes(originalString);
string base64UrlString = Convert.ToBase64String(bytesToEncode)
                             .TrimEnd('=')
                             .Replace('+', '-')
                             .Replace('/', '_');
// Result: "SGVsbG8sIEJhc2U2NCE"

C# encode and decode image to/from Base64:

// Encoding
byte[] imageBytes = File.ReadAllBytes("image.jpg");
string base64ImageString = Convert.ToBase64String(imageBytes);

// Decoding
byte[] decodedImageBytes = Convert.FromBase64String(base64ImageString);
File.WriteAllBytes("decodedImage.jpg", decodedImageBytes);

Base64 encoding for file attachments in C#:

byte[] fileBytes = File.ReadAllBytes("document.pdf");
string base64FileString = Convert.ToBase64String(fileBytes);
// Send or store base64FileString

C# encode and decode JSON to/from Base64:

// Encoding
string jsonString = "{\"name\":\"John\",\"age\":30}";
byte[] jsonBytes = Encoding.UTF8.GetBytes(jsonString);
string base64JsonString = Convert.ToBase64String(jsonBytes);

// Decoding
byte[] decodedJsonBytes = Convert.FromBase64String(base64JsonString);
string decodedJsonString = Encoding.UTF8.GetString(decodedJsonBytes);

Base64 encoding for URLs in C#:

string originalUrl = "https://www.example.com";
byte[] bytesToEncode = Encoding.UTF8.GetBytes(originalUrl);
string base64UrlString = Convert.ToBase64String(bytesToEncode)
                            .TrimEnd('=')
                            .Replace('+', '-')
                            .Replace('/', '_');
// Result: "aHR0cHM6Ly93d3cueGFtYmVyLmNvbQ"

C# convert image to Base64 string:

byte[] imageBytes = File.ReadAllBytes("image.png");
string base64ImageString = Convert.ToBase64String(imageBytes);

Base64 encoding for XML data in C#:

string xmlData = "<root><name>John</name><age>30</age></root>";
byte[] bytesToEncode = Encoding.UTF8.GetBytes(xmlData);
string base64XmlString = Convert.ToBase64String(bytesToEncode);

C# encode and decode binary data to/from Base64:

byte[] binaryData = { 0x01, 0x02, 0x03, 0x04 };
string base64BinaryString = Convert.ToBase64String(binaryData);

byte[] decodedBinaryData = Convert.FromBase64String(base64BinaryString);

Base64 encoding for email attachments in C#:

byte[] attachmentBytes = File.ReadAllBytes("attachment.docx");
string base64AttachmentString = Convert.ToBase64String(attachmentBytes);
// Include base64AttachmentString in email

C# encode and decode PDF to/from Base64:

// Encoding
byte[] pdfBytes = File.ReadAllBytes("document.pdf");
string base64PdfString = Convert.ToBase64String(pdfBytes);

// Decoding
byte[] decodedPdfBytes = Convert.FromBase64String(base64PdfString);
File.WriteAllBytes("decodedDocument.pdf", decodedPdfBytes);

Base64 encoding for database storage in C#:

string dataToStore = "Some sensitive data";
byte[] bytesToStore = Encoding.UTF8.GetBytes(dataToStore);
string base64DataString = Convert.ToBase64String(bytesToStore);
// Store base64DataString in the database

C# encode and decode audio to/from Base64:

byte[] audioBytes = File.ReadAllBytes("audio.mp3");
string base64AudioString = Convert.ToBase64String(audioBytes);

byte[] decodedAudioBytes = Convert.FromBase64String(base64AudioString);

Base64 encoding for secure data transmission in C#:

// Encoding
string sensitiveData = "TopSecret123";
byte[] dataBytes = Encoding.UTF8.GetBytes(sensitiveData);
string base64EncodedData = Convert.ToBase64String(dataBytes);

// Decoding
byte[] decodedDataBytes = Convert.FromBase64String(base64EncodedData);
string decodedData = Encoding.UTF8.GetString(decodedDataBytes);