How to convert to Base64 in C#?

Question

I am using Webforms. There is a certain part of this application where I send, through Ajax, a string Base64, which is the code of an image.

I’m used to using PHP and use the functions base64_encode and base64_decode to make the conversions to Base64.

But in C# I have no idea how to do that.

How to decode a Base64 in C# (and vice versa)?

_{I don’t know if it’s duplicate, I didn’t find anything related to it on the site}

Answer 1

If the code is the manipulation of images then in C# will not use string, will use byte[] probably then the use of:

• System.Text.ASCIIEncoding.ASCII.GetBytes

And

• System.Text.Encoding.UTF8.GetString

They don’t make much sense, supposing I read the picture like this:

byte[] imagem = System.IO.File.ReadAllBytes(@"<caminho da imagem>");

So just pass the variable like this:

string imagebase64 = System.Convert.ToBase64String(imagem);

You don’t have to use string for this.

To decode you must use System.Convert.FromBase64String that will return in byte[] and then you can save the value of this in a file, as you wish, example:

string imagecodificadaembase64 = <valor em string do arquivo ou requisição em bas64>;
byte[] imagemdecodificada = System.Convert.FromBase64String(imagecodificadaembase64);

Answer 2

I took it from here

Encode

public static string Base64Encode(string plainText) {
  var plainTextBytes = System.Text.Encoding.UTF8.GetBytes(plainText);
  return System.Convert.ToBase64String(plainTextBytes);
}

Decode

public static string Base64Decode(string base64EncodedData) {
  var base64EncodedBytes = System.Convert.FromBase64String(base64EncodedData);
  return System.Text.Encoding.UTF8.GetString(base64EncodedBytes);
}