Refresh problem

hsucp2p · December 27th, 2007, 03:05 PM

I am working on a page in .net 1.1, where post data is used at the beginning to retrieve the ID from the database using a dropdownlist. One of the .net server controls on the page is to link to another page using asp:linkbutton and the other control is to link back to the original page using asp:hyperlink with javascript: history.go(-1). The message, "The page cannot be refreshed without resending the information, Click Retry to send the information again, or click Cancel to return to the page that you were trying to view." is received when I clicked on the hyperlink back to the previous page.

There is another page on the same site. It has almost the same functionalities. It has no problem to go back to the previous page. I checked all possible causes in both html page and code behind. I couldn't find any difference between these two pages.

I would appreciate if some one can help me out on this.

Ching

urtrivedi · December 28th, 2007, 12:55 AM

If you want to load same page, on item change in the dropdown list. Click on dropdown in property page you may find postback property. Set it true. so whenever user changes item page will reload.

urt

hsucp2p · December 28th, 2007, 09:59 AM

Hi urt,

The problem was not autopostback on the dropdown list. The problem was the asp:hyperlink. I received the refresh error message when I clicked on the hyperlink and tried to link it back to previous page. Any suggestions? Thanks.

Ching

urtrivedi · December 29th, 2007, 02:48 PM

Could you post your code and error message?

urt

hsucp2p · January 3rd, 2008, 05:01 PM

Hi urt,
Sorry for the late response. My code is as the followings. There are two pages, WebForm1.aspx and WebForm2.aspx. I received an error message "Warning: Page has expired, The page you requested was created using information you submitted in a form...." if I selected one of those selections in the dropdown box and clicked on the link button "View WebForm2 then clicked on "Return to WebForm1" on WebForm2. In order to link it back to the previous page, WebForm1 successfully, the solutions are either I remove HTML Input (I can't do that for business reason) or I remove autopostback in the dropdown box. (I might do that if it is the only solution). So, my question is how I can clear the postback in window.history or change the page id or something in window.history. Thanks.

WebForm1.aspx
<%@ Page language="c#" Codebehind="WebForm1.aspx.cs" AutoEventWireup="false" Inherits="PageHasExpired.WebForm1" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
    <HEAD>
        .....
    </HEAD>
    <body MS_POSITIONING="GridLayout">
        <form id="Form1" method="post" runat="server">
            <div>
                <tr>
                    <td><asp:hyperlink id="hypReturn" NavigateUrl="javascript: window.history.go(-2)" CssClass="hyplink"
                            Runat="server">< Return to WebForm1</asp:hyperlink></td>
                </tr>
                <br>
                <br>
                <tr>
                <td><asp:dropdownlist id="ddlTrialBatchPoint" runat="server" AutoPostBack="True">
                            <asp:ListItem>Select one</asp:ListItem>
                            <asp:ListItem>1</asp:ListItem>
                            <asp:ListItem>2</asp:ListItem>
                            <asp:ListItem>3</asp:ListItem>
                            <asp:ListItem>4</asp:ListItem>
                        </asp:dropdownlist></td>
                </tr>
                <br>
                <br>
                <tr>
                    <td>
                        <asp:LinkButton id="lnkViewPage2" onclick="lnkViewPage2_Click" runat="server" CssClass="hyplink">View WebForm2</asp:LinkButton></td>
                </tr>
                <br>
                <br>
                <tr>
                    <td>
                        <input id="fileName" type="file" size="20" runat="server"></td>
                    <td><asp:requiredfieldvalidator id="reqFileName" runat="server" ErrorMessage="* File name Required" EnableClientScript="False"
                            ControlToValidate="fileName"></asp:requiredfieldvalidator></td>
                </tr>
            </div>
        </form>
    </body>
</HTML>

WebForm1 code behind:
private void Page_Load(object sender, System.EventArgs e)
        {
            // Put user code to initialize the page here
        }

        protected void lnkViewPage2_Click(object sender, System.EventArgs e)
        {
            Server.Transfer("WebForm2.aspx");
        }

WebForm2.aspx
<form id="Form1" method="post" runat="server">
            <div>
                <tr>
                    <td><asp:hyperlink id="hypReturn" Runat="server" NavigateUrl="javascript: window.history.go(-1)">< Return to WebForm1</asp:hyperlink>
                    </td>
                </tr>
                <tr>
                    <td><p><b>Page 2 data.</b></p>
                    </td>
                </tr>
            </div>
        </form>

WebForm2 - no code behind.

ching

urtrivedi · January 4th, 2008, 01:15 AM

simply if you want to reload previous page, then do not user history.go,
instead create hyperlink refereing previous page with complete query string if any.

<a href="previouspage.aspx?par1=val1&par2=val2">Back</a>

urt

hsucp2p · January 4th, 2008, 07:02 PM

Thank you for your suggestion. Ching