无法将System.Byte[]的对象强制转换为类型System.IConvertible

MySqlParameter[] parameters = new MySqlParameter[2];

parameters[0] = new MySqlParameter("?buffer", MySqlDbType.VarBinary) { Value = buffer };

byte[] buffer = System.Text.Encoding.Default.GetBytes (htmlCode);

string htmlCode = System.Text.Encoding.Default.GetString (buffer);