页面恢复

using System;
  2  using System.Web;
  3 using System.Web.SessionState;
  4 using System.Web.UI;
  5 namespace GentleSoft.MyOffice
  6 {
  7 ///<summary>   
  8 /// 页面状态持久化。可保存和恢复页面的ViewState和表单内容   
  9 ///</summary>
 10 publicclass PersistencePage : GentleUtil.Page.Page
 11     {
 12 
 13 ///<summary>   
 14 /// 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）   
 15 ///</summary>
 16 privatebool taoist_IsLoadPageStateFromToSession =false;
 17 
 18 ///<summary>   
 19 /// 页面状态保存到的Session   
 20 ///</summary>
 21 privatestring taoist_PageStateSession ="";
 22 
 23 ///<summary>   
 24 /// 保存页面状态（包括ViewState和表单内容）   
 25 ///</summary>   
 26 ///<param name="sessionName">存储页面状态的session</param>
 27 protectedvoid SavePageStateToSession(string sessionName)
 28         {
 29 
 30 this.taoist_PageStateSession = sessionName;
 31 object state =base.LoadPageStateFromPersistenceMedium();
 32 
 33 //保存ViewState与表单内容   
 34             Pair ps =new Pair();
 35             ps.First = state;
 36             ps.Second =base.DeterminePostBackMode();
 37             Session[sessionName] = ps;
 38         }
 39 
 40 ///<summary>   
 41 /// 重写此方法，如果是从Session中恢复状态则无需触发控件事件   
 42 ///</summary>   
 43 ///<param name="sourceControl"></param>   
 44 ///<param name="eventArgument"></param>
 45 protectedoverridevoid RaisePostBackEvent(IPostBackEventHandler sourceControl, string eventArgument)
 46         {
 47 if (!taoist_IsLoadPageStateFromToSession)
 48             {
 49 base.RaisePostBackEvent(sourceControl, eventArgument);
 50             }
 51         }
 52 
 53 ///<summary>    
 54 /// 重写此方法，只有taoist_IsLoadPageStateFromToSession为true时才从Session中还原ViewState。    
 55 ///</summary>    
 56 ///<returns></returns>
 57 protectedoverrideobject LoadPageStateFromPersistenceMedium()
 58         {
 59 object state;
 60 
 61 if (taoist_IsLoadPageStateFromToSession)
 62             {
 63 //还原ViewState   
 64                 Pair ps = (Pair)Session[taoist_PageStateSession];
 65                 state = ps.First;
 66 //清空当前Session，保证只能恢复一次，防止无效恢复   
 67                 Session[taoist_PageStateSession] =null;
 68             }
 69 else
 70                 state =base.LoadPageStateFromPersistenceMedium();
 71 
 72 return state;
 73         }
 74 
 75 ///<summary>    
 76 /// 重载此方法，增加表单恢复，并设置是否恢复Session   
 77 ///</summary>    
 78 ///<returns></returns>
 79 protectedoverride System.Collections.Specialized.NameValueCollection DeterminePostBackMode()
 80         {
 81 
 82             System.Collections.Specialized.NameValueCollection formContent =base.DeterminePostBackMode();
 83 
 84 if (formContent ==null)
 85             {
 86 //判断是否返回   
 87 if (Request.QueryString["taoist_PageStateSession"] !=null)
 88                 {
 89                     taoist_PageStateSession = Convert.ToString(Request.QueryString["taoist_PageStateSession"]);
 90 if (Session[taoist_PageStateSession] !=null&&!taoist_PageStateSession.Equals(""))
 91                     {
 92 //设置需要还原ViewState   
 93 this.taoist_IsLoadPageStateFromToSession =true;
 94 
 95 //先还原表单   
 96                         Pair ps = Session[taoist_PageStateSession] as Pair;
 97 if (ps !=null)
 98                         {
 99                             formContent = ps.Second as System.Collections.Specialized.NameValueCollection;
100                         }
101                     }
102 
103                 }
104 else
105                 {
106                     Session["mypagestate"] =null;
107                 }
108             }
109 
110 return formContent;
111         }
112 
113     }
114 }