检查文件是否存在

　　　　using System.IO;
　　　　using System.Xml.Serialization;



        public List<Users> userlist = new List<Users>();
        public List<Users> UsersList
        {
            get { return userlist; }
        }

        public void SaveInformation()
        {
            XmlSerializer serializer = new XmlSerializer(typeof(List<Users>));
            string filePath = @"serializeUsers.xml";
            FileStream fs = File.Create(filePath);
            serializer.Serialize(fs,UsersList);
            fs.Close();
        }
        public List<Users> ReadInformation()
        {
            XmlSerializer serializer = new XmlSerializer(typeof(List<Users>));
            string filePath = @"serializeUsers.xml";
            if (!File.Exists(filePath))
            {
               ***************************
            }
            FileStream fs = File.OpenRead(filePath);
            List<Users> lu = (List<Users>)serializer.Deserialize(fs);
            fs.Close();
            return lu;
        }