viewstate issue ?

yuvalk · November 28th, 2003, 09:38 PM

Hi all,
i have a problem which i suspect to be related to the viewstate property.
Im using code-behind to bind a datareader to an asp:dropDownList control.
for the first few times it all seems ok but after that im getting an empty dropdownlist control.
even when i close my sql server i still get the same with NO error regarding the closed sql Server.
"view source" for the resulted page shows:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
    <HEAD>
        <title>WebForm1</title>
        <meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1">
        <meta name="CODE_LANGUAGE" Content="C#">
        <meta name="vs_defaultClientScript" content="JavaScript">
        <meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">
    </HEAD>
    <body MS_POSITIONING="GridLayout">
        <form name="Form1" method="post" action="main.aspx" id="Form1">
<input type="hidden" name="__VIEWSTATE" value="dDwxNTYyMTgwMDUyOzs+GmrvyRI2ZAfwgsocIcvSHNx RvRo=" />

            <select name="packageTypes" id="packageTypes">

</select>
        </form>
    </body>
</HTML>

I guess it something pretty simple.
any1 has any idea ?

Thanks in advance

Yuval Kronenfeld
Web Developer

planoie · November 28th, 2003, 11:15 PM

Are you binding to the drop down every time you load the page? Usually you want to only databind the DDL on the first page load (based on a check of IsPostback). This could be causing a problem, but it doesn't seem like it would result in what you are saying. If you bind the ddl every time, you can end up with events not firing but usually, it doesn't result in missing data.

Peter
------------------------------------------------------
Work smarter, not harder.

yuvalk · November 28th, 2003, 11:29 PM

Hi Peter,
I didnt make the ispostback check .
But i added it now and after trying to run again it still act the same and doesnt care if the sqlServer is on or not.

bellow you will find the webform code and later the code-behind(i use a class library - DataHandler - as Data Access Layer)

<%@ Page language="c#" Codebehind="main.aspx.cs" AutoEventWireup="false" Inherits="WIS.main" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
    <HEAD>
        <title>WebForm1</title>
        <meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1">
        <meta name="CODE_LANGUAGE" Content="C#">
        <meta name="vs_defaultClientScript" content="JavaScript">
        <meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">
    </HEAD>
    <body MS_POSITIONING="GridLayout">
        <form id="Form1" method="post" runat="server" >
            <asp:DropDownList ID="packageTypes" runat=server/>
        </form>
    </body>
</HTML>

'------------------------------------------------------------------
using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using DataHandler ;

namespace WIS
{
    /// <summary>
    /// Summary description for WebForm1.
    /// </summary>
    public class main : System.Web.UI.Page
    {
        protected System.Web.UI.WebControls.DropDownList packageTypes;

        private void Page_Load(object sender, System.EventArgs e)
        {
            if(!IsPostBack)
            {
                DataHandler.DataHandler DataHandler = new DataHandler.DataHandler();
                DataHandler.OpenConn();
                packageTypes.DataSource = DataHandler.getDataReader("SPPackageTypes");
                packageTypes.DataTextField = "type";
                packageTypes.DataValueField = "ID";
                packageTypes.DataBind();
            }
        }

        #region Web Form Designer generated code
        override protected void OnInit(EventArgs e)
        {
            //
            // CODEGEN: This call is required by the ASP.NET Web Form Designer.
            //
            InitializeComponent();
            base.OnInit(e);
        }

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {

        }
        #endregion
    }
}

Yuval Kronenfeld
Web Developer

planoie · November 28th, 2003, 11:59 PM

If it doesn't break when you change the way it's getting data, then I would say there might be something wrong with the way you get the data. What you have in your page codebehind looks just fine.

Peter
------------------------------------------------------
Work smarter, not harder.

yuvalk · November 29th, 2003, 07:13 AM

unless i miss something here - getting the data seems to be ok - it worked the first few times...but after that - nothing

planoie · November 29th, 2003, 11:33 PM

If the DDL shows up right the first time, but doesn't after that, and you are only populating the data the first time, then perhaps something else is causing the data to change. Do you have any other events in the page that are manipulating that DDL's data? Otherwise, I don't know what to tell you.

Peter
------------------------------------------------------
Work smarter, not harder.

yuvalk · November 30th, 2003, 04:18 AM

i have no other events.
but i agree with you - it seems like something else is wrong.
strange.
10x for the help anyway.I appriciate it.
Yuval.