"Object reference not set" error when Login button clicked RSS

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  rpk2006

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  "Object reference not set" error when Login button clicked

  May 24, 2012 11:39 AM|LINK

  I have a default ASP.NET 4.0 Login Form which is auto-generated with an empty ASP.NET 4 application.

  On the Login Form I have added two DropDown Controls and I pass the selected item text and values in session variables.

  When the Login button is clicked, these session variables are created and page is supposed to redirected to another page.

  Below is the code of the Login Button Click event:

  protected void LoginButton_Click(object sender, EventArgs e)
      {
          reuse reuseableMethodsClass = new reuse();
          VerifyUser verifyUser = new VerifyUser();
          DropDownList ddlFy = LoginUser.FindControl("ddlFyYear") as DropDownList;
          DropDownList ddlOffice = LoginUser.FindControl("ddlOffice") as DropDownList;
          verifyUser.EnteredUserName = LoginUser.UserName;
          verifyUser.EnteredPassword = LoginUser.Password;
          bool verified = verifyUser.GetLoginStatus();
          if (verified)
          {
              Session.Add("ASP.NET_SessionId", Session.SessionID.ToString());
              Session.Add("FinancialYear", ddlFy.SelectedItem.Text);
   Session.Add("LoggedOfficeName", ddlOffice.SelectedItem.Text);
   Session.Add("LoggedOfficeID", ddlOffice.SelectedItem.Value.ToString());
  
              Response.Redirect("~/Views/ListView.aspx");
          }
          else
              reuseableMethodsClass.CustomClientMessage("Failed", this.Page);
      }

  
  
  

  The problem is when I click the Login button, an error is displayed in the lines where I add DropDown values to the Session.

  Error is: Object reference not set to an instance of an object.

  Error is displayed in the three lines:

              Session.Add("FinancialYear", ddlFy.SelectedItem.Text); 
   Session.Add("LoggedOfficeName", ddlOffice.SelectedItem.Text);
   Session.Add("LoggedOfficeID", ddlOffice.SelectedItem.Value.ToString());
  

  I think when I select option from the DropDown, the new value is not retained after postback.

  • Edited by rpk2006 on May 24, 2012 11:39 AM
  • Edited by rpk2006 on May 24, 2012 11:40 AM
  • Edited by rpk2006 on May 24, 2012 11:41 AM
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  hoopslife

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  Re: "Object reference not set" error when Login button clicked

  May 24, 2012 11:53 AM|LINK

  Do you have viewstate turned on for the controls?

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  rpk2006

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  Re: "Object reference not set" error when Login button clicked

  May 24, 2012 11:55 AM|LINK

  They were ON by default. I turned them OFF but the problem is still there.

  I never cared about turning them OFF before.

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  hoopslife

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  Re: "Object reference not set" error when Login button clicked

  May 24, 2012 01:03 PM|LINK

  Well, you deffinetly need them on to have the values postback.  Have you tried stepping through your code to see which specific control isn't sending the value over?  Or is it all 3?

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  rpk2006

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  Re: "Object reference not set" error when Login button clicked

  May 25, 2012 10:57 AM|LINK

  All three. I set the breakpoint.

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  roopeshreddy

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  Re: "Object reference not set" error when Login button clicked

  May 25, 2012 11:04 AM|LINK

  Hi,

  Before adding the DropDownList value to Session, you need to check whether the DropDownList is null or not!

  if(ddlFy != null)
  {
    Session.Add("FinancialYear", ddlFy.SelectedItem.Text);
  }

  Hope it helps u...

   

  Thanks & Regards
  Roopesh Reddy C
  Roopesh's Space
  
  • Marked as answer by dalong zhang - msft on May 31, 2012 09:26 AM
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  hoopslife

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  Re: "Object reference not set" error when Login button clicked

  May 25, 2012 11:44 AM|LINK

  Can you post the html?  Make sure you have runat="server" for each controller.

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