實現類似QQ記住密碼的功能

記住用戶的密碼，一般瀏覽器都有這個功能，基於C/S結構的軟件實現這個功能也有很多方法，這裏採用簡單的文件流保存用戶名及密碼的方法來實現這個功能。

Person類，模擬用戶

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace LMSys.Model
{
    /// <summary>
    /// 用戶基類
    /// </summary>
    [Serializable]
    public class Person
    {
        #region 屬性
        /// <summary>
        /// 用戶名
        /// </summary>
        string userName;
        public string UserName
        {
            get { return userName; }
            set { userName = value; }
        }

        /// <summary>
        /// 密碼
        /// </summary>
        string userPassword;
        public string UserPassword
        {
            get { return userPassword; }
            set { userPassword = value; }
        }

        /// <summary>
        /// 權限
        /// </summary>
        int power;
        public int Power
        {
            get { return power; }
            set { power = value; }
        }
        #endregion
    }
}

RememberUser類，記住用戶，但採用的是二進制的方式保存數據

using LMSys.Model;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.Serialization.Formatters.Binary;
using System.Text;
using System.Threading.Tasks;

namespace LMSys.BLL
{
    public class RememberUser
    {
        private static Dictionary<string, Person> persons = new Dictionary<string, Person>();

        /// <summary>
        /// 構造函數，讀取文件流
        /// </summary>
        public RememberUser()
        {
            FileStream fs = new FileStream("Data.bin", FileMode.OpenOrCreate);
            if (fs.Length > 0)
            {
                BinaryFormatter bf = new BinaryFormatter();
                persons = bf.Deserialize(fs) as Dictionary<string, Person>;
            }
            fs.Close();
        }

        /// <summary>
        /// 返回保存的用戶列表
        /// </summary>
        /// <returns></returns>
        public Dictionary<string, Person> GetList()
        {
            return persons;
        }

        /// <summary>
        /// 添加新用戶
        /// </summary>
        /// <param name="person"></param>
        public void AddRemember(Person person)
        {
            FileStream fs = new FileStream("Data.bin", FileMode.Create);
            BinaryFormatter bf = new BinaryFormatter();
            if (persons.ContainsKey(person.UserName))//若已存在用戶，先移除該用戶
            {
                persons.Remove(person.UserName);
            }
            persons.Add(person.UserName, person);//再添加該用戶，防止用戶密碼更新
            bf.Serialize(fs, persons);
            fs.Close();
        }
    }
}

這樣，界面就可以很容易調用該類實現記住密碼的功能。