asp.net的页面状态保存与恢复

 

using System;using System.Web;using System.Web.SessionState;using System.Web.UI;/** 说    明：需要保存状态的页面需要继承此类，使用方法如下：* 1、保存状态时使用SavePageStateToSession方法，例子：private void Button2_Click(object sender, System.EventArgs e){this.SavePageStateToSession("mypagestate");Response.Redirect("WebForm2.aspx");}mypagestate 为要将页面状态保存到的Session的名称2、恢复状态需向页面传递taoist_PageStateSession参数，例子private void Button1_Click(object sender, System.EventArgs e){Response.Redirect("WebForm1.aspx?taoist_PageStateSession=mypagestate");}参数名为taoist_PageStateSession，其值为要恢复WebForm1.aspx页面所使用的Session* * */    /// <summary>    /// 页面状态持久化。可保存和恢复页面的ViewState和表单内容    /// </summary>namespace MKP.Common{    public class PersistencePage : System.Web.UI.Page    {        /// <summary>        /// 是否从Session中恢复状态（此值来控制LoadPageStateFromPersistenceMedium的取值规则以及回发事件RaisePostBackEvent执行与否，防止状态恢复时重复执行控件事件）        /// </summary>        private bool taoist_IsLoadPageStateFromToSession = false;        /// <summary>        /// 页面状态保存到的Session        /// </summary>        private string taoist_PageStateSession = "";        /// <summary>        /// 保存页面状态（包括ViewState和表单内容）        /// </summary>        /// <param name="sessionName">存储页面状态的session</param>        protected void SavePageStateToSession(string sessionName)        {            this.taoist_PageStateSession = sessionName;            object state = base.LoadPageStateFromPersistenceMedium();            //保存ViewState与表单内容            Pair ps = new Pair();            ps.First = state;            ps.Second = base.DeterminePostBackMode();            Session[sessionName] = ps;        }        /// <summary>        /// 重写此方法，如果是从Session中恢复状态则无需触发控件事件        /// </summary>        /// <param name="sourceControl"></param>        /// <param name="eventArgument"></param>        protected override void RaisePostBackEvent(IPostBackEventHandler sourceControl, string eventArgument)        {            if (!taoist_IsLoadPageStateFromToSession)            {                base.RaisePostBackEvent(sourceControl, eventArgument);            }        }        /// <summary>         /// 重写此方法，只有taoist_IsLoadPageStateFromToSession为true时才从Session中还原ViewState。         /// </summary>         /// <returns></returns>         protected override object LoadPageStateFromPersistenceMedium()        {            object state;            if (taoist_IsLoadPageStateFromToSession)            {                //还原ViewState                Pair ps = (Pair)Session[taoist_PageStateSession];                state = ps.First;                //清空当前Session，保证只能恢复一次，防止无效恢复                Session[taoist_PageStateSession] = null;            }            else                state = base.LoadPageStateFromPersistenceMedium();            return state;        }        /// <summary>         /// 重载此方法，增加表单恢复，并设置是否恢复Session        /// </summary>         /// <returns></returns>         protected override System.Collections.Specialized.NameValueCollection DeterminePostBackMode()        {            System.Collections.Specialized.NameValueCollection formContent = base.DeterminePostBackMode();            if (formContent == null)            {                //判断是否返回                if (Request.QueryString["taoist_PageStateSession"] != null)                {                    taoist_PageStateSession = Convert.ToString(Request.QueryString["taoist_PageStateSession"]);                    if (Session[taoist_PageStateSession] != null && !taoist_PageStateSession.Equals(""))                    {                        //设置需要还原ViewState                        this.taoist_IsLoadPageStateFromToSession = true;                        //先还原表单                        Pair ps = Session[taoist_PageStateSession] as Pair;                        if (ps != null)                        {                            formContent = ps.Second as System.Collections.Specialized.NameValueCollection;                        }                    }                }            }            return formContent;        }    }}