Error in Session

**Eliyahu Goldin** · Jun 6 '06, 07:15 AM

Re: Error in Session

PageLoad event fires before OnClick one. That's why Session["UserName"] is
null in PageLoad.

Eliyahu

"Gunawan" <jgun98.milis@g mail.com> wrote in message
news:eQa$MTTiGH A.4572@TK2MSFTN GP05.phx.gbl...[color=blue]
> Hi All,
> I am using VS 2005 to build this page.
> One the code file I use this code
> using System;
>
> using System.Data;
>
> using System.Configur ation;
>
> using System.Collecti ons;
>
> using System.Web;
>
> using System.Web.Secu rity;
>
> using System.Web.UI;
>
> using System.Web.UI.W ebControls;
>
> using System.Web.UI.W ebControls.WebP arts;
>
> using System.Web.UI.H tmlControls;
>
>
>
> public partial class one : System.Web.UI.P age
>
> {
>
> protected void Page_Load(objec t sender, EventArgs e)
>
> {
>
> if (Session["FirstLoadT ime"] == null)
>
> {
>
> Session["FirstLoadT ime"] = DateTime.Now.To String("T");
>
> }
>
> Label1.Text = "Page first loaded at " +
> Session["FirstLoadT ime"].ToString();
>
>
>
> if (IsPostBack)
>
> {
>
> Label1.Text += " Welcome back, "
>
> + Session["UserName"].ToString();
>
> }
>
> }
>
> protected void Button1_Click(o bject sender, EventArgs e)
>
> {
>
> if (Session["UserName"] == null)
>
> {
>
> Session["UserName"] = TextBox1.Text;
>
> }
>
>
>
> }
>
> }
>
>
>
> But why I always get this error though I have type something in the
> textbox1
>
>
>
>
>
> Server Error in '/WebData' Application.
> --------------------------------------------------------------------------------
>
> Object reference not set to an instance of an object.
> Description: An unhandled exception occurred during the execution of the
> current web request. Please review the stack trace for more information
> about the error and where it originated in the code.
>
> Exception Details: System.NullRefe renceException: Object reference not set
> to an instance of an object.
>
> Source Error:
>
> Line 22: if (IsPostBack)
> Line 23: {
> Line 24: Label1.Text += " Welcome back, "
> Line 25: + Session["UserName"].ToString();
> Line 26: }
>
>
>
>
>
>[/color]

**Gunawan** · Jun 6 '06, 07:45 AM

Re: Error in Session

If I Using this code
using System;

using System.Data;

using System.Configur ation;

using System.Collecti ons;

using System.Web;

using System.Web.Secu rity;

using System.Web.UI;

using System.Web.UI.W ebControls;

using System.Web.UI.W ebControls.WebP arts;

using System.Web.UI.H tmlControls;

public partial class one : System.Web.UI.P age

{

protected void Page_Load(objec t sender, EventArgs e)

{

string sUserName;

if (Session["FirstLoadT ime"] == null)

{

Session["FirstLoadT ime"] = DateTime.Now.To String("T");

}

Label1.Text = "Page first loaded at " +
Session["FirstLoadT ime"].ToString();

if (IsPostBack && Session["UserName"] != null)

{

sUserName = (string)Session["UserName"];

Label1.Text += " Welcome back, "

+ sUserName + "!"

+" IsPostBack: " + IsPostBack.ToSt ring();

}

else

{

Label1.Text += " Welcome back, unknown user."

+" IsPostBack: " + IsPostBack.ToSt ring();

}

}

protected void Button1_Click(o bject sender, EventArgs e)

{

Session["UserName"] = TextBox1.Text;

}

}

I need click button1 twice to make username appear on label1.

Why? any idea?

TIA

Gun

**Gunawan** · Jun 6 '06, 07:55 AM

Re: Error in Session

I see.... Now I can figure out what happened.

I would to know what is the best practice if I want to do something like
this

If user click button1 on one.aspx I would like to perform some action before
directing user to another page (two.aspx).
Action that I want to perform effecting Session["DataMS"]
Session["DataMS"] use in page two.aspx.

does button1 onclick perform before pageload on two.aspx?

TIA
Gun

"Eliyahu Goldin" <removemeegoldi n@monarchmed.co m> wrote in message
news:e2fqoeTiGH A.1276@TK2MSFTN GP03.phx.gbl...[color=blue]
> PageLoad event fires before OnClick one. That's why Session["UserName"] is
> null in PageLoad.
>
> Eliyahu
>
> "Gunawan" <jgun98.milis@g mail.com> wrote in message
> news:eQa$MTTiGH A.4572@TK2MSFTN GP05.phx.gbl...[color=green]
>> Hi All,
>> I am using VS 2005 to build this page.
>> One the code file I use this code
>> using System;
>>
>> using System.Data;
>>
>> using System.Configur ation;
>>
>> using System.Collecti ons;
>>
>> using System.Web;
>>
>> using System.Web.Secu rity;
>>
>> using System.Web.UI;
>>
>> using System.Web.UI.W ebControls;
>>
>> using System.Web.UI.W ebControls.WebP arts;
>>
>> using System.Web.UI.H tmlControls;
>>
>>
>>
>> public partial class one : System.Web.UI.P age
>>
>> {
>>
>> protected void Page_Load(objec t sender, EventArgs e)
>>
>> {
>>
>> if (Session["FirstLoadT ime"] == null)
>>
>> {
>>
>> Session["FirstLoadT ime"] = DateTime.Now.To String("T");
>>
>> }
>>
>> Label1.Text = "Page first loaded at " +
>> Session["FirstLoadT ime"].ToString();
>>
>>
>>
>> if (IsPostBack)
>>
>> {
>>
>> Label1.Text += " Welcome back, "
>>
>> + Session["UserName"].ToString();
>>
>> }
>>
>> }
>>
>> protected void Button1_Click(o bject sender, EventArgs e)
>>
>> {
>>
>> if (Session["UserName"] == null)
>>
>> {
>>
>> Session["UserName"] = TextBox1.Text;
>>
>> }
>>
>>
>>
>> }
>>
>> }
>>
>>
>>
>> But why I always get this error though I have type something in the
>> textbox1
>>
>>
>>
>>
>>
>> Server Error in '/WebData' Application.
>> --------------------------------------------------------------------------------
>>
>> Object reference not set to an instance of an object.
>> Description: An unhandled exception occurred during the execution of the
>> current web request. Please review the stack trace for more information
>> about the error and where it originated in the code.
>>
>> Exception Details: System.NullRefe renceException: Object reference not
>> set to an instance of an object.
>>
>> Source Error:
>>
>> Line 22: if (IsPostBack)
>> Line 23: {
>> Line 24: Label1.Text += " Welcome back, "
>> Line 25: + Session["UserName"].ToString();
>> Line 26: }
>>
>>
>>
>>
>>
>>[/color]
>
>[/color]

**Eliyahu Goldin** · Jun 6 '06, 08:25 AM

Re: Error in Session

Can you put the redirecting statement in the button1 onclick?

Eliyahu

"Gunawan" <jgun98.milis@g mail.com> wrote in message
news:%23hlJ35Ti GHA.4716@TK2MSF TNGP03.phx.gbl. ..[color=blue]
>I see.... Now I can figure out what happened.
>
> I would to know what is the best practice if I want to do something like
> this
>
> If user click button1 on one.aspx I would like to perform some action
> before directing user to another page (two.aspx).
> Action that I want to perform effecting Session["DataMS"]
> Session["DataMS"] use in page two.aspx.
>
> does button1 onclick perform before pageload on two.aspx?
>
> TIA
> Gun
>
> "Eliyahu Goldin" <removemeegoldi n@monarchmed.co m> wrote in message
> news:e2fqoeTiGH A.1276@TK2MSFTN GP03.phx.gbl...[color=green]
>> PageLoad event fires before OnClick one. That's why Session["UserName"]
>> is null in PageLoad.
>>
>> Eliyahu
>>
>> "Gunawan" <jgun98.milis@g mail.com> wrote in message
>> news:eQa$MTTiGH A.4572@TK2MSFTN GP05.phx.gbl...[color=darkred]
>>> Hi All,
>>> I am using VS 2005 to build this page.
>>> One the code file I use this code
>>> using System;
>>>
>>> using System.Data;
>>>
>>> using System.Configur ation;
>>>
>>> using System.Collecti ons;
>>>
>>> using System.Web;
>>>
>>> using System.Web.Secu rity;
>>>
>>> using System.Web.UI;
>>>
>>> using System.Web.UI.W ebControls;
>>>
>>> using System.Web.UI.W ebControls.WebP arts;
>>>
>>> using System.Web.UI.H tmlControls;
>>>
>>>
>>>
>>> public partial class one : System.Web.UI.P age
>>>
>>> {
>>>
>>> protected void Page_Load(objec t sender, EventArgs e)
>>>
>>> {
>>>
>>> if (Session["FirstLoadT ime"] == null)
>>>
>>> {
>>>
>>> Session["FirstLoadT ime"] = DateTime.Now.To String("T");
>>>
>>> }
>>>
>>> Label1.Text = "Page first loaded at " +
>>> Session["FirstLoadT ime"].ToString();
>>>
>>>
>>>
>>> if (IsPostBack)
>>>
>>> {
>>>
>>> Label1.Text += " Welcome back, "
>>>
>>> + Session["UserName"].ToString();
>>>
>>> }
>>>
>>> }
>>>
>>> protected void Button1_Click(o bject sender, EventArgs e)
>>>
>>> {
>>>
>>> if (Session["UserName"] == null)
>>>
>>> {
>>>
>>> Session["UserName"] = TextBox1.Text;
>>>
>>> }
>>>
>>>
>>>
>>> }
>>>
>>> }
>>>
>>>
>>>
>>> But why I always get this error though I have type something in the
>>> textbox1
>>>
>>>
>>>
>>>
>>>
>>> Server Error in '/WebData' Application.
>>> --------------------------------------------------------------------------------
>>>
>>> Object reference not set to an instance of an object.
>>> Description: An unhandled exception occurred during the execution of the
>>> current web request. Please review the stack trace for more information
>>> about the error and where it originated in the code.
>>>
>>> Exception Details: System.NullRefe renceException: Object reference not
>>> set to an instance of an object.
>>>
>>> Source Error:
>>>
>>> Line 22: if (IsPostBack)
>>> Line 23: {
>>> Line 24: Label1.Text += " Welcome back, "
>>> Line 25: + Session["UserName"].ToString();
>>> Line 26: }
>>>
>>>
>>>
>>>
>>>
>>>[/color]
>>
>>[/color]
>
>[/color]

Error in Session

Error in Session

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