ViewState 页面级状态保持

将整个页面的 EnableViewState 设置为 false ，可以减少带宽压力，同时，将需要保持状态的控件 EnableViewState 设置为 True ，即可实现该控件的状态保持。

TestViewState.aspx

ViewState.aspx.cs

using System;

using System.Collections;

using System.Configuration;

using System.Data;

using System.Linq;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.HtmlControls;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Xml.Linq;

namespace WebApplication1.Web

{

public partial class ViewState : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e)

{

if (Page.IsPostBack == false)

{

ViewState["DisText"] = "还没点击呢";

}

}

protected void btn_Click(object sender, EventArgs e)

{

if (ViewState["DisText"] != null && ViewState["DisText"].ToString() != "")

this.lable.Text = ViewState["DisText"].ToString();

}

protected void ddl_SelectedIndexChanged(object sender, EventArgs e)

{

string sname = this.ddl.SelectedValue;

ViewState["DisText"] = "我选择的是："+ sname;

}

}

}