页面做完后，查看源代码，有个<input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE" value=“”

Question

input里的value的值是一段很长的字符串，这是什么，是正常吗？为什么会产生这么长的值？怎样能使他不产生呢？/////////////////////////////////////////
<input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE" value="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">

Answer 1

.Net Web页面使用的所谓ViewState，用于内部保存交换数据的，多少取决于页面上使用ViewState的元素。

Answer 2

这个假设是10K，占用多少网络带宽？你算过吗？如果不想要状态管理能力，关闭整个网站的 EnableViewState 开关好了。请你好好测试一下，还能不能编写出有自动化状态的程序。

Answer 3

控件的视图状态，在客户端用一个隐藏域存储，需要时可以设置控件的EnableViewState=false禁用它，不过不是任何时候都可以禁用的。

Answer 4

viewstate，保持数据状态的隐藏表单域。这么长是因为使用viewstate的控件太多了，数据量大，比如gridview控件。系统默认打开的，可以禁用，设置enableviewstate=false;。

Answer 5

如果它确实很大（10K根本不算大！而你贴的远远小于10K），你可以写这个代码：using System;
using System.IO;
using System.Linq;
using System.Runtime.Serialization.Formatters.Binary;
using System.Threading;
using System.Web.UI;public class VPage : Page
{
    static private DirectoryInfo _Dir;    private static DirectoryInfo Dir
    {
        get
        {
            if (_Dir == null)
            {
                _Dir = new DirectoryInfo(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "App_Data"));
                if (!_Dir.Exists)
                    _Dir.Create();
                _Dir = new DirectoryInfo(Path.Combine(_Dir.FullName, "ViewState"));
                if (!_Dir.Exists)
                    _Dir.Create();
            }
            return _Dir;
        }
    }    protected override object LoadPageStateFromPersistenceMedium()
    {
        PageStatePersister ps = this.PageStatePersister;
        ps.Load();
        if (ps.ControlState != null)
            ps.ControlState = 反序列化对象((string)ps.ControlState);
        if (ps.ViewState != null)
            ps.ViewState = 反序列化对象((string)ps.ViewState);
        return new Pair(ps.ControlState, ps.ViewState);
    }    protected override void SavePageStateToPersistenceMedium(object state)
    {
        PageStatePersister ps = this.PageStatePersister;
        if (state is Pair)
        {
            ps.ControlState = ((Pair)state).First;
            ps.ViewState = ((Pair)state).Second;
        }
        else
            ps.ViewState = state;
        if (ps.ControlState != null)
            ps.ControlState = 序列化对象(ps.ControlState);
        if (ps.ViewState != null)
            ps.ViewState = 序列化对象(ps.ViewState);
        ps.Save();
    }    private object 反序列化对象(string stateID)
    {
        if (stateID == null)
            return null;        object state = Cache[stateID];
        if (state == null)
            using (var stream = File.OpenRead(Path.Combine(Dir.FullName, stateID)))
                state = new BinaryFormatter().Deserialize(stream);
        else
            Cache.Remove(stateID);
        return state;
    }    private string 序列化对象(object obj)
    {
        string stateID = Guid.NewGuid().ToString("N");
        Cache.Insert(stateID, obj, null, DateTime.Now.AddMinutes(5), System.Web.Caching.Cache.NoSlidingExpiration);
        using (var stream = File.Create(Path.Combine(Dir.FullName, stateID)))
            new BinaryFormatter().Serialize(stream, obj);
        return stateID;
    }    static VPage()
    {
        ThreadPool.QueueUserWorkItem(h =>
        {
            var et = DateTime.Now.AddMinutes(-30);
            Dir.GetFiles()
                .Where(f => f.LastAccessTime < et)
                .ToList()
                .ForEach(f =>
                {
                    try
                    {
                        f.Delete();
                    }
                    catch { }
                });
        });
    }
}把这个class作为你的Paged的父类而继承。

Answer 6

我把enableviewstate=false关闭，会不会有影响啊？

Answer 7

如果enableviewstate=false，那么画面的数据就不会保持，意思就是你在输入框中输入了一个值，等提交之后，再次刷新画面时，这个值不会自动的显示出来。你试一试就知道什么效果了

Answer 8

我不知道微软是如何让这样一种蹩脚设计通过测试的。我个人用过一段时间的asp.net webform，我个人感觉，这是微软一款比较失败的产品，即使许多很多人用它取得了辉煌成果，但是从设计角度看，它违背了web程序最基本的理念。一个简单的html报文交换机制被活生生的复杂化，真是不理解微软当初是怎么想的。至于这个ViewState，这是asp.net webform的毒瘤，但却是它很重要的一个组成。所以，说了这么多，我觉得你不如换个web框架……