写了个缓存 Session 的类，欢迎大家指正。

 

    public class SessionCache
    {
        Get New Cache Table#region Get New Cache Table

        public static DataTable CreateCacheTable()
        {
            DataTable table = new DataTable("SessionCache");

            DataColumn column;

            column = new DataColumn();
            column.ColumnName = "SessionId";
            column.DataType = System.Type.GetType("System.String");
            table.Columns.Add(column);

            column = new DataColumn();
            column.ColumnName = "UserCode";
            column.DataType = System.Type.GetType("System.Int32");
            table.Columns.Add(column);

            column = new DataColumn();
            column.ColumnName = "LoginName";
            column.DataType = System.Type.GetType("System.String");
            table.Columns.Add(column);

            column = new DataColumn();
            column.ColumnName = "HostAddress";
            column.DataType = System.Type.GetType("System.String");
            table.Columns.Add(column);

            column = new DataColumn();
            column.ColumnName = "PlatForm";
            column.DataType = System.Type.GetType("System.String");
            table.Columns.Add(column);

            column = new DataColumn();
            column.ColumnName = "BrowserType";
            column.DataType = System.Type.GetType("System.String");
            table.Columns.Add(column);

            column = new DataColumn();
            column.ColumnName = "StartTime";
            column.DataType = System.Type.GetType("System.DateTime");
            table.Columns.Add(column);

            column = new DataColumn();
            column.ColumnName = "LoginTime";
            column.DataType = System.Type.GetType("System.DateTime");
            table.Columns.Add(column);

            column = new DataColumn();
            column.ColumnName = "EndTime";
            column.DataType = System.Type.GetType("System.DateTime");
            table.Columns.Add(column);

            return table;
        }

        #endregion

        public static void SessionStart(DataTable table, string strSessionId, string strHostAddress, string strPlatForm, string strBrowserType, DateTime dtNow)
        {
            DataRow row = table.NewRow();

            DateTime now = DateTime.Now;

            row["SessionId"] = strSessionId;
            row["HostAddress"] = strHostAddress;
            row["PlatForm"] = strPlatForm;
            row["BrowserType"] = strBrowserType;
            row["StartTime"] = dtNow;

            table.Rows.Add(row);
        }

        public static void SessionEnd(DataTable table, string strSessionId, DateTime dtNow)
        {
            DataRow[] rows = table.Select(string.Format("SessionId = '{0}'", strSessionId));

            if( rows.Length == 0 )
                return;

            rows[0]["EndTime"] = dtNow;

            string connString = ConfigurationSettings.AppSettings["ConnString"];
            using( SqlConnection conn = new SqlConnection(connString) )
            {
                SqlCommand cmd = new SqlCommand();
                cmd.Connection = conn;

                if( rows[0]["UserCode"] != DBNull.Value )
                {
                    cmd.CommandText = "INSERT INTO SessionLog(SessionId, UserCode, HostAddress, PlatForm, BrowserType, StartTime, LoginTime, EndTime) VALUES(@SessionId, @UserCode, @HostAddress, @PlatForm, @BrowserType, @StartTime, @LoginTime, @EndTime)";
                    cmd.Parameters.Add("@UserCode", Convert.ToInt32(rows[0]["UserCode"].ToString()));
                    cmd.Parameters.Add("@LoginTime", Convert.ToDateTime(rows[0]["LoginTime"].ToString()));
                }
                else
                {
                    cmd.CommandText = "INSERT INTO SessionLog(SessionId, HostAddress, PlatForm, BrowserType, StartTime, EndTime) VALUES(@SessionId, @HostAddress, @PlatForm, @BrowserType, @StartTime, @EndTime)";
                }

                cmd.Parameters.Add("@SessionId", rows[0]["SessionId"].ToString());
                cmd.Parameters.Add("@HostAddress", rows[0]["HostAddress"].ToString());
                cmd.Parameters.Add("@PlatForm", rows[0]["PlatForm"].ToString());
                cmd.Parameters.Add("@BrowserType", rows[0]["BrowserType"].ToString());
                cmd.Parameters.Add("@StartTime", Convert.ToDateTime(rows[0]["StartTime"].ToString()));
                cmd.Parameters.Add("@EndTime", Convert.ToDateTime(rows[0]["EndTime"].ToString()));

                conn.Open();
                cmd.ExecuteNonQuery();
                conn.Close();
            }

            table.Rows.Remove(rows[0]);
        }

        public static void UserLogin(DataTable table,string strSessionId, int intUserCode, string strUserName, DateTime dtNow)
        {
            DataRow[] rows = table.Select(string.Format("SessionId = '{0}'", strSessionId));

            if( rows.Length == 0 )
                return;

            rows[0]["UserCode"] = intUserCode;
            rows[0]["LoginName"] = strUserName;
            rows[0]["LoginTime"] = dtNow;
        }
    }

    public class Global : System.Web.HttpApplication
    {
        /**//// <summary>
        /// 必需的设计器变量。
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        public static string ErrorMessage = "NULL";

        public Global()
        {
            InitializeComponent();
        }    
        
        protected void Application_Start(Object sender, EventArgs e)
        {
            try
            {
                Application["SessionCount"] = 0;
                Application["SessionCache"] = SessionCache.CreateCacheTable();
            }
            catch(Exception ex)
            {
                Global.ErrorMessage = ex.Message + "<br>" + ex.Source + "<br>" + ex.StackTrace;
            }
        }
 
        protected void Session_Start(Object sender, EventArgs e)
        {
            try
            {
                Application.Lock();
                Application["SessionCount"] = (int)Application["SessionCount"] + 1;
                SessionCache.SessionStart(
                    (System.Data.DataTable)Application["SessionCache"], 
                    Session.SessionID, 
                    Request.UserHostAddress, 
                    Request.Browser.Platform, 
                    Request.Browser.Type, 
                    DateTime.Now
                    );
                Application.UnLock();
            }
            catch(Exception ex)
            {
                Global.ErrorMessage = ex.Message + "<br>" + ex.Source + "<br>" + ex.StackTrace;
            }
        }

        protected void Application_BeginRequest(Object sender, EventArgs e)
        {

        }

        protected void Application_EndRequest(Object sender, EventArgs e)
        {

        }

        protected void Application_AuthenticateRequest(Object sender, EventArgs e)
        {

        }

        protected void Application_Error(Object sender, EventArgs e)
        {

        }

        protected void Session_End(Object sender, EventArgs e)
        {
            try
            {
                Application.Lock();
                Application["SessionCount"] = (int)Application["SessionCount"] - 1;
                SessionCache.SessionEnd(
                    (System.Data.DataTable)Application["SessionCache"], 
                    Session.SessionID, 
                    DateTime.Now
                    );
                Application.UnLock();
            }
            catch(Exception ex)
            {
                Global.ErrorMessage = ex.Message + "<br>" + ex.Source + "<br>" + ex.StackTrace;
            }
        }

        protected void Application_End(Object sender, EventArgs e)
        {

        }
            
        Web 窗体设计器生成的代码#region Web 窗体设计器生成的代码
        /**//// <summary>
        /// 设计器支持所需的方法 - 不要使用代码编辑器修改
        /// 此方法的内容。
        /// </summary>
        private void InitializeComponent()
        {    
            this.components = new System.ComponentModel.Container();
        }
        #endregion
    }