ASP.NET

Session being lost in a simple test webpage

31-Dec-09 9:40

You are in wrong Forum. This is ASP.NET Forum. !! Smile | :)

Abhijit Jana | Codeproject MVP
Web Site : abhijitjana.net
Don't forget to click "Good Answer" on the post(s) that helped you.

jpegny31-Dec-09 9:29

jpegny

31-Dec-09 9:29

Hi,

I'm using visual studio 2008 and it's built in development webserver, with C# as the codebehind language.

I'm trying to make a simple webapp in which you click a button which sets a session var (that part is working) and in the pageload
i'm checking to see if it's a postback and if the session is not null. problem is that every time the session is null.
I have done this successfully before with visual studio 2003 and on IIS.

Here is the relevant code:

<br />
protected void Button1_Click(object sender, EventArgs e)<br />
        {<br />
            Session["testvar"] = 25;<br />
<br />
            /*<br />
            if (Session["testvar"] == null)<br />
                Response.Write("s is null");<br />
            else<br />
                Response.Write("s is NOT null");<br />
            <br />
            */<br />
        }<br />
<br />
<br />
        protected void Page_Load(object sender, EventArgs e)<br />
        {<br />
            if (IsPostBack)<br />
            {<br />
                int x;<br />
<br />
                //x = (int)Session["testvar"];<br />
<br />
                <br />
                if (Session["testvar"] == null)<br />
                    Response.Write("test var is null");<br />
                else<br />
                {<br />
                    x = (int)Session["testvar"];<br />
                    TextBox1.Text = x.ToString();<br />
                }<br />
<br />
                <br />
<br />
            }<br />
        }<br />
<br />
<br />

Any help is appreciated.
Thanks

Abhijit Jana31-Dec-09 9:39

31-Dec-09 9:39

What session mode is selected in web.config ? What is the session timeout time ?

Abhijit Jana | Codeproject MVP
Web Site : abhijitjana.net
Don't forget to click "Good Answer" on the post(s) that helped you.

jpegny31-Dec-09 9:42

jpegny

31-Dec-09 9:42

I've haven't set either of those, everything is left to default in web.config, the only thing I enabled was debugging.

From my readings the default of inProc should be sufficient.

^Sir Dot Net31-Dec-09 11:55

^Sir Dot Net

31-Dec-09 11:55

Based on the code above, you have to click the button twice in order for the session var to show in the textbox.
this is because the execution goes in this order:
Page Load
--You click Button
Page Load
Button Click

jpegny31-Dec-09 12:30

jpegny

31-Dec-09 12:30

Yes that was it.

I ended up using the prerender event.

Thanks

Re: Web page compiler error

pd695-Jan-10 23:35

pd69

5-Jan-10 23:35

Try putting the following line in Web.config under the System.Web:

"sessionState mode="InProc" timeout="30" cookieless="false" /sessionState"

Lemme know if it worked !

Web page compiler error

mavoc31-Dec-09 7:50

mavoc

31-Dec-09 7:50

I built a asp.net site solved all the debugger errors and tested it thoroughly, however when I published the webpages I get this compiler error message:

A name was started with an invalid character. Error processing resource 'file:///C:/Users/Matthew/Documents/Visual Studio 2...

<%@ page language="VB" autoeventwireup="false" inherits="special, App_Web_7wnhu2hb" %>
-^

Note: the code is stored in a filename.aspx.vb file in the solution and not embedded into the the filename.aspx like
<source type="text/vbscript"> code here </source>

This is my first time posting so if you need more info or the code for the website please ask and I will show it. I'm new to web programming, so whatever help you can give would be greatly appreciated. Thanks!

Abhijit Jana31-Dec-09 8:23

Re: Web page compiler error

31-Dec-09 8:23

From where your web application is running ? Is it from VS IDE or from IIS ?
If it is from IIS, did you set the ASP.NET version on Virtual Directory ?

Please let me know. I will try to help you out !!

and Happy new year !! Big Grin | :-D

Abhijit Jana | Codeproject MVP
Web Site : abhijitjana.net
Don't forget to click "Good Answer" on the post(s) that helped you.

mavoc1-Jan-10 7:18

mavoc

1-Jan-10 7:18

Good question. I just published the website to a local folder on my computer and ran it from there, but I get the same error when I upload and run it from the online server as well.

Re: Web page compiler error

Abhijit Jana2-Jan-10 9:21

Re: Web page compiler error [modified]

2-Jan-10 9:21

Sorry for late response. Does your problem resolved ?

Happy new year !

Abhijit Jana | Codeproject MVP
Web Site : abhijitjana.net
Don't forget to click "Good Answer" on the post(s) that helped you.

mavoc4-Jan-10 6:50

mavoc

4-Jan-10 6:50

~~No it's not resolved yet, but I think I might need something extra in my webspace to help the browser run the VB code than just the .aspx file. So any suggestions are welcome.~~

Actually correction, I don't know how to get the website I designed in VB to a finished product that I can put on the webspace I have. When I try to and then run the result in a web browser I get the aforementioned error.

modified on Wednesday, January 6, 2010 9:22 PM

Getting function value

Hema Bairavan31-Dec-09 4:47

Hema Bairavan

31-Dec-09 4:47

Hi all,
i am developing one website, in which i have following code,

function GetCatDesc(Int)
{
var vardesc= "";
switch (Int)
{
case 1:
vardesc += "Employements";
break;

case 2:
vardesc += "Automobiles";
break;

}

return vardesc;
}

and

<tr><td align="left" ><asp:Label runat="server" Text="GetCatDesc(<%#Eval("fao_ddlcategory")%>"></asp:Label></td></tr>

for this label the value will be coming while page loading or some other on search click.

i want that function to be executed and the result of that function to be set as text for the label.

i dont know the asp syntax, can any one help me,
thanks in advance

Abhishek Sur31-Dec-09 6:41

Abhishek Sur

31-Dec-09 6:41

just put

Text = javascript:GetCatDesc('<%# Eval("fao_ddlcategory")%>'"

instead of what you have.
The execution depends on where you added this server control. #Eval works in Repeater, but you cant do this in a server side control I think.

Check with this solution. Hope it corrects. Otherwise ask me with the whole control where you placed this Eval.
Smile | :)

Abhishek Sur
Don't forget to click "Good Answer" if you like this Solution.
My Latest Articles-->
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Simplify Code Using NDepend
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Hema Bairavan31-Dec-09 6:49

Hema Bairavan

31-Dec-09 6:49

what ever you said is correct,
i m using the same in the repeater only.

<asp:repeater id="rptProducts" runat="server" >
<ItemTemplate>
<table cellpadding="5" cellspacing="0" style="background-color:lightyellow">
<tr>
<tr><td><asp:LinkButton runat="server" ID="i" OnClientClick="mypopup()" CommandName=<%#Eval("fao_addsnumber")%> > <%#Eval("fao_subcategory")%> </asp:LinkButton></td></tr>
<tr><td align="left" ><asp:Label runat="server" Text="javascript:GetCatDesc(<%#Eval("fao_ddlcategory")%>"></asp:Label></td></tr>
<tr><td align="left"><%#Eval("fao_description")%></td></tr>
<tr><td align="Left"><%#Eval("fao_city")%> <%#(" ,")%> <%#Eval("fao_state")%> <%#(" ,")%> <%#Eval("fao_country")%></td>
<%--<asp:HiddenField runat="server" ID="test" Value=<%#Eval("fao_addsnumber")%>/>--%>
</tr>
</tr>
<br />
<br />
</table>
</ItemTemplate>
</asp:repeater>

this is my coding regarding the function..
i added label for checking , its not working though..
even after removing that also its coming like text javascript:GetC...
like this

thans for ur response

Re: Getting function value [modified]

Abhishek Sur31-Dec-09 7:15

Abhishek Sur

31-Dec-09 7:15

Ya, I got your problem. Actually, if you dont place runat=server for a control inside Repeater, it will evaluate data correctly. For a control having runat="server" you need to do this from your codeBehind.

The ItemDataBound event is the best candidate for you.

Add asp:Repeater OnItemDataBound="RepeaterItemEventHandler" in the control

public void RepeaterItemEventHandler(object sender, RepeaterItemEventArgs e)
{
    if(e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternateItem)
    {
         Label lbl = e.Item.FindControl("lblitem") as Label;
         lbl.Text = DataBinder.Eval(e.Item.DataItem, "fao_subcategory");
         
    }
}

also to remind you, you can set the javascript there, but it will not execute when text property gets loaded. Rather put a RegisterStartupScript which will modify the data.

this.ClientScript.RegisterStartupScript(this.GetType, lbl.ClientId, "GetCatDesc('" + lbl.ClientId + "');" , true);<br />

like this.

Just modify this according to what you need. Do this inside the RepeaterItemEventHandler

Abhishek Sur
Don't forget to click "Good Answer" if you like this Solution.
My Latest Articles-->
Windows7 API Code Pack

Simplify Code Using NDepend
Basics of Bing Search API using .NET

Hema Bairavan31-Dec-09 8:06

Hema Bairavan

31-Dec-09 8:06

thanks abishek,
i agree and i will work and revert you as per the method you said,

but my question is you said putting runat="server" i.e server side control cannot be used directly inside the repeater, look below

<tr><td align="left" >javascript:GetCatDesc(<%#Eval("fao_ddlcategory")%>)</td></tr>
<tr><td align="left"><%#Eval("fao_description")%></td></tr>

here the description is printing correctly and why not my funcion??

i have doubt on this can you clear me please if u dont mind,

and am sorry if i disturb you.

and

lbl.Text = DataBinder.Eval(e.Item.DataItem, "fao_subcategory");
in this line am getting
Error 26 Cannot implicitly convert type 'object' to 'string'. An explicit conversion exists (are you missing a cast?)

thanks in advamce

modified on Thursday, December 31, 2009 2:16 PM

asp.net vb radiobuttonlist object reference

Abhishek Sur31-Dec-09 8:39

Abhishek Sur

31-Dec-09 8:39

Hema Bairavan wrote:
you said putting runat="server" i.e server side control cannot be used directly inside the repeater

what... No no. You can put runat="server" control inside ItemTemplate of a Repeater and only those controls that you state runat="server" could be found during ItemDataBound Event.

I said you cant specify server tags in the designer when you place runat="server"

<asp:Label runat="server" Text="<%# Eval("fao_ddlcategory")%>" is not possible
rather
you use
<span><%# Eval("fao_ddlcategory")%>" </span> which is client side control, or rather you directly place in the TD block.

Hema Bairavan wrote:
here the description is printing correctly and why not my funcion??

Ya.. It will print. Actually writing javascript:func in the html is meaningless. javascript protocol is used to define that the line prior to it is a javascript one. If you want to place/run a script, place it below all controls in a script block like
<script type="text/javascript">
GetCatDesc(val);
</script>

If you place your javascript in RegisterStarupScript it will appear at the bottom of the page and thus find all the control in it.

Hema Bairavan wrote:
in this line am getting
Error 26 Cannot implicitly convert type 'object' to 'string'.

Yes of course, you must do
lbl.Text = DataBinder.Eval(e.Item.DataItem, "fao_subcategory") as string;

Hope you get the issues right..

Happy New Year from me. Rose | [Rose]

Abhishek Sur
Don't forget to click "Good Answer" if you like this Solution.
My Latest Articles-->
Windows7 API Code Pack

Simplify Code Using NDepend
Basics of Bing Search API using .NET

janetb9931-Dec-09 4:31

janetb99

31-Dec-09 4:31

I don't know until the page is created how many radiobuttonlists I will need. So, I create them and store the number in a hidden label. But, when I want to get the selection from the radiobuttonlist on postback, I keep getting a object reference error. I've tried finding the control without a findControl, with a findControl and with a master page content reference and findControl. No luck. Any help appreciated...

Dim myConStr As String = ""
If lblSidCount.Text <> "0" Then
    Dim x As Integer = 1, y As Integer = Convert.ToInt32(lblSidCount.Text)
    Do While x <= y
        Dim myContent As ContentPlaceHolder = CType(Page.Master.FindControl("ContentPlaceHolder1"), ContentPlaceHolder)
        Dim radConStr As New RadioButtonList
        radConStr = CType(myContent.FindControl("rad" & x.ToString), RadioButtonList)
        myConStr &= radConStr.SelectedItem.Text & "~"
        x = x + 1
    Loop
    myConStr = Left(myConStr, Len(myConStr) - 1)
End If

Re: asp.net vb radiobuttonlist object reference

janetb994-Jan-10 10:33

janetb99

4-Jan-10 10:33

This seems to work - am I crazy for doing this?

Private radCon As RadioButtonList()<br />
Protected Overrides Sub OnInit(ByVal e As EventArgs)<br />
    MyBase.OnInit(e)<br />
    If (Request("str") = 1) Then<br />
        Dim myList As dsSql = New dsSql()   ''''instantiate the function to get dataset<br />
        Dim ds As New Data.DataSet<br />
        ds = myList.dsConSessionTimes(Request("eid"))<br />
        If ds.Tables("conSessionTimes").Rows.Count > 0 Then<br />
            radCon = New RadioButtonList(ds.Tables("conSessionTimes").Rows.Count - 1) {}<br />
            Dim i As Integer = 0<br />
                Dim rad As RadioButtonList = New RadioButtonList()<br />
                rad.ID = "rad" + i.ToString()<br />
                rad.DataSource = ds.Tables("conSessions")<br />
                rad.DataTextField = ds.Tables("conSessions").Columns("session_name").ToString<br />
                rad.DataBind()<br />
                rad.SelectedIndex = 0<br />
                phConcurrent.Controls.Add(rad)<br />
                radCon(i) = rad<br />
            For Each j As Data.DataRow In ds.Tables("conSessionTimes").Rows<br />
                Dim rad As RadioButtonList = New RadioButtonList()<br />
                rad.ID = "rad" + i.ToString()<br />
                rad.DataSource = ds.Tables("conSessions")<br />
                rad.DataTextField = ds.Tables("conSessions").Columns("session_name").ToString<br />
                rad.DataBind()<br />
                rad.SelectedIndex = 0<br />
                phConcurrent.Controls.Add(rad)<br />
                radCon(i) = rad<br />
                i = i + 1<br />
            Next<br />
        End If<br />
    End If<br />
End Sub

Need some expert advices on ViewState

James Shao31-Dec-09 4:26

James Shao

31-Dec-09 4:26

Hi, I am trying to build a website that provides stock information like the one in Yahoo Finance:

http://finance.yahoo.com/echarts?s=MSFT#chart7:symbol=msft;range=3m;indicator=bollinger+volume;charttype=line;crosshair=on;ohlcvalues=0;logscale=on;source=undefined

All the source and analytical data is already there, however I am trying to implement a mechanism that allows users to click and graph additional chart on each mouse click, meaning there'll be multiple postbacks. The problem is with each postback, existing charts plotted by users should remain on the page, and only the new chart is added. Smile | :)

In the link above, if you click on "TECHNICAL INDICATORS", a dropdown list appears allowing users to add additional chart to the page, without destroying existing charts that's currently on the page. This is exactly the kind of function I want to have for my website.

So how could I implement this mechanism using ASP.NET? I am thinking this is a Viewstate issue. Should my goal be maintaining the viewstate of the chart itself? Or should I perhaps store user-defined inputs temporarily into a control (perhaps a label control)and maintain the viewstate of that, based on which the chart will be plotted? Confused | :confused:

Or is there a more elegant approach to this?

I'd greatly appreciate any suggestions! Thank you.

James Shao31-Dec-09 20:19

James Shao

31-Dec-09 20:19

Could someone please give me some suggestions if possible? Thanks!

Anurag Gandhi31-Dec-09 20:57

Anurag Gandhi

31-Dec-09 20:57

Try using ajax and avoid postback.
Asp.Net Ajax provides you a number of ways to stay on the page and add
contents to the same page from the server.

Hope this will help.

Anurag Gandhi.
http://www.gandhisoft.com
Life is a computer program and every one is the programmer of his own life.

James Shao1-Jan-10 4:26

James Shao

1-Jan-10 4:26

Thanks for the reply Anurag. I thought with AJAX, there'll still be postbacks, just partial postback in the AJAX panel? Thus if I put my chart in the panel, it'll still post back and redraw the chart every time I click the "ADD New Chart" button right?

Thanks!