ViewState存储到服务端

需要把ViewState保存到服务器端的页面继承此类。由于ViewState的数据量太大而产生Client与Server进行交互时的网络传输数据量过大从而导致效率低下的现象。为了解决这个问题可以采用服务器端ViewState的方法，将不影响页面显示的对象保存到服务器端的硬盘上。

using System;
using System.IO;
using System.Threading;
using System.Web.UI;

public class VPage : Page { static private DirectoryInfo Dir = new DirectoryInfo(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, @"App_Data\ViewState\"));

    static VPage()
    {
        if (!Dir.Exists)
            Dir.Create();
    }

    protected override object LoadPageStateFromPersistenceMedium()
    {
        string viewStateID = (string)((Pair)base.LoadPageStateFromPersistenceMedium()).Second;
        string stateStr = (string)Cache[viewStateID];
        if (stateStr == null)
        {
            string fn = Path.Combine(Dir.FullName, viewStateID);
            stateStr = File.ReadAllText(fn);
        }
        else
            Cache.Remove(viewStateID);
        return new ObjectStateFormatter().Deserialize(stateStr);
    }

    protected override void SavePageStateToPersistenceMedium(object state)
    {
        string value = new ObjectStateFormatter().Serialize(state);
        string viewStateID = (DateTime.Now.Ticks + (long)this.GetHashCode()).ToString(); //产生离散的id号码  
        string fn = Path.Combine(Dir.FullName, viewStateID);
        ThreadPool.QueueUserWorkItem((obj) => File.WriteAllText(fn, value)); //或者只写 File.WriteAllText(fn, value)
        Cache.Insert(viewStateID, value);
        base.SavePageStateToPersistenceMedium(viewStateID);
    }

    static private bool _flag = false;

    protected override void _disibledevent="color: #000000">
        {
        }
    }
}