I'm using javascript to capture a text field value and put it in a hidden field value, and then submit the associated form. In Page_Load I extract and act on the hidden field value. All this works fine, except...
The hidden field value that is entered persists when the page is refreshed (ie. reloaded) via the browser UI, causing the field value to be recognized and acted on again in Page_Load.
I've tried to blank out the hidden field value in several different client-side and server side events, and can't seem to make it go away.
Any suggestions on how to fix this would be appreciated.
Thanks!
================= page and javascript
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "
<html xmlns=" >
<head runat="server">
<title>Untitled Page</title>
<script src=JScript.js></script>
</head>
<BODY onload="javascript:ResetHiddenFields()"; onunload="javascript:ResetHiddenFields()";>
<form id="form1" method="post" runat="server">
<div>
<input type=hidden id="Hidden1" runat=server value = "" />
<input id="Button1" type="button" style="z-index:103; left: 180px; position: absolute; top: 8px;" onClick="javascript:Button1Click()" value="button" />
<input id="Text1" style="z-index: 104; left: 16px; position: absolute; top: 8px"
type="text" />
</div>
</form>
<script language=javascript>
function GetElem(varString){return document.getElementById(varString) }
function Button1Click() {
GetElem("Hidden1").value = ""
GetElem("Hidden1").value = GetElem("Text1").value
alert("Hidden1 = " + GetElem("Hidden1").value);
document.forms[0].submit();
}
function ResetHiddenFields() {
alert("resetting hidden value")
GetElem("Hidden1").value = ""
}
</script>
</body>
</html>
============= code behind
Partial Class _Default
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not IsPostBack Then
Me.Hidden1.Value = ""
End If
MsgBox("in Page_Load")
If IsPostBack Then
MsgBox("about to check hidden1")
If Trim(Me.Hidden1.Value) <> "" Then ' doesn't help, because not blank at this point
MsgBox("found non-blank hidden value = " & Me.Hidden1.Value)
Me.Hidden1.Value = "" ' doesn't help
End If
End If
End Sub
Protected Sub Page_LoadComplete(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.LoadComplete
Me.Hidden1.Value = "" ' didn't work
End Sub
Protected Sub Page_PreLoad(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreLoad
'Me.Hidden1.Value = "" ' this shuts it off before load, so not found, not good
End Sub
Protected Sub Page_PreRender(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreRender
'Me.Hidden1.Value = "" ' didn't work
End Sub
Protected Sub form1_Unload(ByVal sender As Object, ByVal e As System.EventArgs) Handles form1.Unload
'Me.Hidden1.Value = "" ' didn't work
End Sub
Protected Sub Page_PreRenderComplete(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreRenderComplete
'Me.Hidden1.Value = "" ' didn't work
End Sub
Protected Sub Hidden1_PreRender(ByVal sender As Object, ByVal e As System.EventArgs) Handles Hidden1.PreRender
'Me.Hidden1.Value = "" ' didn't work
End Sub
End Class
===============================================
The hidden field value that is entered persists when the page is refreshed (ie. reloaded) via the browser UI, causing the field value to be recognized and acted on again in Page_Load.
I've tried to blank out the hidden field value in several different client-side and server side events, and can't seem to make it go away.
Any suggestions on how to fix this would be appreciated.
Thanks!
================= page and javascript
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "
<html xmlns=" >
<head runat="server">
<title>Untitled Page</title>
<script src=JScript.js></script>
</head>
<BODY onload="javascript:ResetHiddenFields()"; onunload="javascript:ResetHiddenFields()";>
<form id="form1" method="post" runat="server">
<div>
<input type=hidden id="Hidden1" runat=server value = "" />
<input id="Button1" type="button" style="z-index:103; left: 180px; position: absolute; top: 8px;" onClick="javascript:Button1Click()" value="button" />
<input id="Text1" style="z-index: 104; left: 16px; position: absolute; top: 8px"
type="text" />
</div>
</form>
<script language=javascript>
function GetElem(varString){return document.getElementById(varString) }
function Button1Click() {
GetElem("Hidden1").value = ""
GetElem("Hidden1").value = GetElem("Text1").value
alert("Hidden1 = " + GetElem("Hidden1").value);
document.forms[0].submit();
}
function ResetHiddenFields() {
alert("resetting hidden value")
GetElem("Hidden1").value = ""
}
</script>
</body>
</html>
============= code behind
Partial Class _Default
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not IsPostBack Then
Me.Hidden1.Value = ""
End If
MsgBox("in Page_Load")
If IsPostBack Then
MsgBox("about to check hidden1")
If Trim(Me.Hidden1.Value) <> "" Then ' doesn't help, because not blank at this point
MsgBox("found non-blank hidden value = " & Me.Hidden1.Value)
Me.Hidden1.Value = "" ' doesn't help
End If
End If
End Sub
Protected Sub Page_LoadComplete(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.LoadComplete
Me.Hidden1.Value = "" ' didn't work
End Sub
Protected Sub Page_PreLoad(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreLoad
'Me.Hidden1.Value = "" ' this shuts it off before load, so not found, not good
End Sub
Protected Sub Page_PreRender(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreRender
'Me.Hidden1.Value = "" ' didn't work
End Sub
Protected Sub form1_Unload(ByVal sender As Object, ByVal e As System.EventArgs) Handles form1.Unload
'Me.Hidden1.Value = "" ' didn't work
End Sub
Protected Sub Page_PreRenderComplete(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreRenderComplete
'Me.Hidden1.Value = "" ' didn't work
End Sub
Protected Sub Hidden1_PreRender(ByVal sender As Object, ByVal e As System.EventArgs) Handles Hidden1.PreRender
'Me.Hidden1.Value = "" ' didn't work
End Sub
End Class
===============================================
