Question

Have some long base64 string, which must be formated with New Line every 72 byte and converted to byte array.

Have:

Convert.ToBase64String(Convert.FromBase64String("..."), Base64FormattingOptions.InsertLineBreaks)

But it inserts new line every 76 byte.
And how can i convert it back to byte array with preserved new lines?

Answer 1

set string into StringBuilder and use method Insert() in loop

var sb = new StringBuilder("the string");
for (int i = 72; i < sb.Length; i+=74)//72 + "\r\n"
{
    sb.Insert(i, "\r\n");
}