How to convert a file into byte of array and how to convert the Byte array into file[?]
This is how you read the file into a byte array:
FileStream fs = new FileStream(fileOne, FileMode.Open);
byte[] rawData = new byte[fs.Length];
fs.Read(rawData, 0, (int)fs.Length);
For the opposite operation, use the "Write" method instead and also change the "FileMode" in the consttuctor to "FileMode.Create".