Multiuser problem in Asp.net

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Dear friends,

Here, i've used public static string A; variable in my application.
Suppose, user1 hav A="1" and now user2 come to this form and he has A=2.
So, in this case original value of A for user1(which is A=1) replaced with user2(which is now A=2), But i want to keep both of the value saprately for both the users..

Note :
1) i used public string A; but during postback it lost its value.

i dont want to use session variable for this.

sample coding part for reference-->

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Data.SqlTypes;
using System.Data.SqlClient;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using CrystalDecisions.Web;
using CrystalDecisions.Shared;
using CrystalDecisions.CrystalReports.Engine;

public partial class PO_REG : System.Web.UI.Page
{
   
    public static string A; 
    public static string _print; 
    public void Page_Init(object sender, EventArgs e)
    {
        if (_print == "P")
        {
            ViewReport();
        }
    }
       #endregion

    protected void btnShowReport_Click(object sender, ImageClickEventArgs e)
    {
        _print = "P";
        A = Rdbtn.SelectedValue;        
        ViewReport()
    }

    private void ViewReport()
    {
        ReportDocument crystalReport = new ReportDocument();
        if (A == "1")
        {
            crystalReport.Load(Server.MapPath("sample1.rpt"));
        }
        else if (A == "2")
        {
            crystalReport.Load(Server.MapPath("sample2.rpt"));
        }
    }

any help would be highly appriciated....
thank you.

Posted 4-Nov-12 22:18pm

Vikas_Shukla_89

Updated 4-Nov-12 23:06pm

v7

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Tiwari Avinash · Answer 1 · 2012-11-04T23:23:00

Solution 2

Why not to hold the value A in a viewstate and use update panels for asynchronous post backs. it will be much helpful in multi user applications

Posted 4-Nov-12 23:23pm

Tiwari Avinash

Comments

Vikas_Shukla_89 5-Nov-12 5:27am

Thanks dear for reply..
but im not using ajax.

Baji Jabbar · Answer 2 · 2012-11-04T23:01:00

Solution 1

Why can't you use "Rdbtn.SelectedValue" directly in the ViewReport() routine.

C#

if (Rdbtn.SelectedValue == "1")
{
    crystalReport.Load(Server.MapPath("sample1.rpt"));
}
else if (Rdbtn.SelectedValue == "2")
{
    crystalReport.Load(Server.MapPath("sample2.rpt"));
}

Then another thing we can try is using switch Case; which is a better way to increase the performance.

[Update]: I didnt noticed you have used public static string _print in the code ; whats it for? Some logical mistake is there; I beleive.

Posted 4-Nov-12 23:01pm

Baji Jabbar

Updated 4-Nov-12 23:08pm

v3

Comments

Vikas_Shukla_89 5-Nov-12 5:05am

Bcoz, when user clicks print button in crystal reportviewer then it will fire Page_init event of page.. so, its value for (Rdbtn.SelectedValue) will not there. it will show you null value only..

Ankur^\m/ 5-Nov-12 5:13am

Then another thing we can try is using switch Case; which is a better way to increase the performance
I disagree. For just 2 conditional statements, there won't be any difference. Switch cases are good from readability perspective as well but if there are few conditional statements, if-else is just fine.

Vikas_Shukla_89 5-Nov-12 5:15am

yeah.. ri8

Baji Jabbar 5-Nov-12 5:30am

:thumbsup:
For sure Switch Case is better way than if else conditions not only for readability but for performance too. Yeah for few conditional statements we cant notice any difference

Vikas_Shukla_89 5-Nov-12 5:14am

if (_print == "P"){ViewReport();}
Well, this is for, i want to run this code only if user have already clicked on the asp:button --> ShowReport, otherwise not. dat is y..

Baji Jabbar 5-Nov-12 5:27am

This approach is not needed.

Vikas_Shukla_89 5-Nov-12 5:33am

ok, but that is not a problem.. kindly forget that.
my problem is, value of A overwritten by the value of another user..

Baji Jabbar 5-Nov-12 5:35am

that happens when you use static variable. Did you tried my solution. It will work if you are not loosing the radiobutton state. Try it ( if not ) and give feedback on that.

Vikas_Shukla_89 5-Nov-12 5:49am

if i use if(Rdbtn.SelectedValue == "1") directly..
will i get its value during Page_Init??
Answer is not, dat is why i am using variable there.

now, if i'll not use Page_Init then if user clicks on print or export button in reportviewer then it is showing me an error "Load report failed.."

Baji Jabbar 5-Nov-12 5:56am

Remove your codes from init block , try SelecteValue or SelecteItem.Value. Hope this works , still I don't know why you need that code in Page_Init.

Vikas_Shukla_89 5-Nov-12 6:00am

i did this, report displayed properly for 1st time, but its giving me an error when user tries to print or export reports from crystalreportviewer.

Baji Jabbar 5-Nov-12 6:03am

So it works ! What error you are getting, Did you tried debugging it. From where is the error thrown?

Vikas_Shukla_89 5-Nov-12 6:08am

"Load Report Failed.." this error im getting.
but its giving me an error when user tries to print or export reports from crystalreportviewer.becoz page_init is not there..
Now, when i put above page_init code then it is working fine except multiuser problem..

is there any way, i can use to avoid this but i dont want to use session..

Ankur^\m/ 5-Nov-12 5:25am

Then another thing we can try is using switch Case; which is a better way to increase the performance
I disagree. For just 2 conditional statements, there won't be any difference. Switch cases are good from readability perspective as well but if there are few conditional statements, if-else is just fine.
PS: Sorry I meant to post the comment to the answerer. Re-posting it.

Baji Jabbar 5-Nov-12 5:32am

I replied to your original comment. Thanks Ankur for correcting me .
Cheers :)

manognya kota · Answer 3 · 2012-11-05T01:08:00

Hi,

Correct me if i am wrong.Did you try usng hidden field?

<asp:HiddenField ID="hdnValue" runat="server" Value="Secret Value" />

In that way you can make your variable as public string A.
Assign the hidden variable while assigning the string variable.
On Postback reassign the string variable using the hidden variable.

Hope this helps.