MemoryStream ms = new MemoryStream();
ICryptoTransform transformEncode = new ToBase64Transform();
//Base64编码
CryptoStream csEncode = new CryptoStream(ms, transformEncode, CryptoStreamMode.Write);
CryptoStream csEncrypt = new CryptoStream(csEncode, crypt.CreateEncryptor(), CryptoStreamMode.Write);
System.Text.UTF8Encoding enc = new System.Text.UTF8Encoding();
byte[] rawData = enc.GetBytes(text);