Prevent page refresh on pressing F5 - c#

I have Created form with Server Side control like button..and also have written event on that..
Now runtime after click on the button i have refreshed the page by pressing F5.Page_load is executing fine but button1_click() event also firing...So how can i stop this event execution in this scenario.Please suggest me

Short Answer: Not possible
Longer Answer: No web site can block the browser's functionality as that would be a serious security concern for the browser.

Welcome to web development, there is no way to stop the page from refreshing and reposting, this is entirely a browser behavior.
There are work arounds though; one simple thing that you can do is after processing your button click, you can redirect the browser back to the page so that a refresh will not include a repost of your button press. Obviously this might require some other state management system (rather than view-state), maybe you can store your state in the Session.

<script type="text/javascript" language="javascript">
function checkKeyCode(evt)// for F5 disable
{
var evt = (evt) ? evt : ((event) ? event : null);
var node = (evt.target) ? evt.target : ((evt.srcElement) ? evt.srcElement : null);
if (event.keyCode == 116)//disable F5
{
evt.keyCode = 0;
return false
}
if (event.keyCode == 123) {
evt.keyCode = 0;
return false
}
if (event.keyCode == 93) {
evt.keyCode = 0;
return false
}
if (event.altKey == true && event.keyCode == 115) //disable alt-F4
{
evt.keyCode = 0;
return false
}
//alert(event.keyCode);
}
document.onkeydown = checkKeyCode;
</script>
Post this script on your master page or where u want to block F5 button.

You could potentially use:
window.onbeforeunload = function ()
{
return false;
}
This will display a prompt asking the user if they want to navigate away and may not be desired. (Plus, I don't know the extent of support)

The poster is using ASP.NET WebForms. In MVC, using the Post-Redirect-Get pattern, this would not be a problem.
But this has been solved for Webforms since 2004 (and even before that - I wrote a simple ticket solution in 2001) with this article: http://msdn.microsoft.com/en-us/library/ms379557.aspx
Basically the author creates a unique ticket associated with each request, and removes the validity of the ticket on first postback. Any accidental (or malicious) subsequent postbacks are ignored. It's wrapped up in a base page so it should be easy to add to any Webforms solution.

Its not really page refresh that you want to block, its page re-POST.
As already said, it's not possible on the client side because the refresh will replay what the browser did on the last action.
But you can trap it on the server side because the server can hold some infos to control the request.
The easiest way is to put a sort of RequestID in a hidden field on Page Load, store it somewhere like in the Session. And control its value on next POST to valid the request then override it to avoid re-POST with the same RequestID.
Maybe there's a better way :)
Your 'problem' is similar to a user double-click horror behavior : ASP.Net double-click problem

Do you have to refresh the page on the click of the button? Could you rewire the button to make an ajax call to submit the data? If so, then you would not need to worry about the page re-submitting on refresh.

The only solution for the F5 refresh problem is Response.Redirect. Please see my post on this topic.
https://stackoverflow.com/questions/12596152/asp-net-f5-browser-refresh-duplicate-record/12596153#12596153

I got some code that doesn't allow you to press F5 and/or Ctrl + R:
<!DOCTYPE html>
<html>
<head>
<title>
Key code test!
</title>
<script type="text/javascript">
var x, ctrlKeyPressed = false;
function keyDown(e){
x = e.charCode || e.keyCode;
document.getElementById("key").innerHTML = x;
if(x == 17) {
ctrlKeyPressed = true;
}
if(ctrlKeyPressed && x == 82) {
e.preventDefault();
} else if(x == 116) {
e.preventDefault();
}
}
function keyUp(e) {
x = e.charCode || e.keyCode;
if(x == 17) {
ctrlKeyPressed = false;
}
}
window.onload = function () {
document.onkeydown = function (e) {
keyDown(e);
};
document.onkeyup = function (e) {
keyUp(e);
};
}
</script>
</head>
<body>
Press a key!
<br/>
Key code: <div style="display:inline;" id="key">Nothing</div>
</body>
</html>

Related

disable browser back button javascript

I am using MVC 4 with java script.
Today's i have a requirement to disable to back button in all browsers, need to prevent to go-back to previous page(home page) after click on log-out button with the help of back button of browsers.
Help Me thanks.
Try this
JavaScript Code Sample
javascript code to all the pages where we need to disable the browser back button.
<script type="text/javascript">
//Disable Back Button In All Browsers.
function DisableBackButtonAllBrowsers() {
window.history.forward()
};
DisableBackButtonAllBrowsers();
window.onload = DisableBackButtonAllBrowsers;
window.onpageshow = function (evts) { if (evts.persisted) DisableBackButtonAllBrowsers(); };
window.onunload = function () { void (0) };
</script>
ActionResult code sample in mvc 4
Code for response to ActionResult for log-out in MVC 4. i.e.
/// <summary> /// Logs user out and renders login <see cref="View"/> /// </summary> /// <returns>Login <see cref="View"/></returns>
public ActionResult Logout()
{
//Disable back button In all browsers.
Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.Cache.SetExpires(DateTime.Now.AddSeconds(-1));
Response.Cache.SetNoStore();
FormsAuthentication.SignOut();
return View("Login");
}
Try this, may it will help you.
Link: http://hightechnology.in/how-to-disable-browser-back-button-in-asp-net-using-javascript/
Javascript Code:
<script type = "text/javascript" >
function preventBack(){window.history.forward();}
setTimeout("preventBack()", 0);
window.onunload=function(){null};
</script>
You can use as below :
<script type="text/javascript" language="javascript">
function DisableBackButton() {
window.history.forward()
}
DisableBackButton();
window.onload = DisableBackButton;
window.onpageshow = function(evt) { if (evt.persisted) DisableBackButton() }
window.onunload = function() { void (0) }
</script>
Possible duplicate..
there is a solution mentioned befor here:
set cachebality to noCache..
Page.Response.Cache.SetCacheability(HttpCacheability.NoCache)
Disable browser "back" button
Disable browser's back button
Ideally you want to prevent your session history from getting populated in the first place.
location.replace(url)
From: https://developer.mozilla.org/en-US/docs/Web/API/Location/replace
The Location.replace() method replaces the current resource with the one at the provided URL. After using replace() the current page will not be saved in session History, meaning the user won't be able to use the back button to navigate to it.
If the session history is empty, the back button is disabled. If your app depends heavily on form submission, jQuery makes it easy to convert form variables to a query string for use with location.replace.
function submitForm() {
// this eliminates issues with the back button
window.location.replace('?' + jQuery.param(jQuery('form').serializeArray()));
}

Enter Does Not Work For Submit, ASP.NET Page Refreshes and Doesn't Search

I am working with an ASP.NET site with a C# back end. There is a .Master page where the tag is, and other search pages on the site will search when you hit enter after filling out the form. However we have one page that has a few text boxes and when you hit enter to search, it appears to just refresh and reload the page without searching. In order to search you have to hit the search button (which is an igtxt:WebImageButton ). All of the solutions I have found to this issue so far involve people using javascript to call some kind of function on submit. As far as I know there is no javascript being called when you hit the search button, it is all in the C# code. Once again I find myself searching SO and other sites for an answer but none of the solutions seem to fit my situation. The form tag is as follows:
<form id="form1" runat="server">
The web image buttons call a btn_SearchClick function that runs the search code. But since the form is started in the .Master file I can't edit that as it would effect all other pages as well. Is there any way to have enter call the btn_SearchClick from the form without having to put it in the form tag? I'm not sure what would've changed to cause this behavior on one page and none of the others.
if (!IsPostBack)
{
TextBox1.Attributes.Add("onKeyPress",
"doClick('" + btnSearch.ClientID + "',event)");
}
<SCRIPT type=text/javascript>
function doClick(buttonName,e)
{
//the purpose of this function is to allow the enter key to
//point to the correct button to click.
var key;
if(window.event)
key = window.event.keyCode; //IE
else
key = e.which; //firefox
if (key == 13)
{
//Get the button the user wants to have clicked
var btn = document.getElementById(buttonName);
if (btn != null)
{ //If we find the button click it
btn.click();
event.keyCode = 0
}
}
}
</SCRIPT>
or u can use default button.it's work while cursor's in this box
protected void Page_Load(object sender, EventArgs e)
{
this.Form.DefaultButton = this.btnSubmit.UniqueID;
}
Add some jquery to control the Enter key behavior on your textbox. Something like this:
$(function() {
$('#<%=txtTextbox.ClientID%>').keypress(function (e) {
if (e.which == 13) {
e.preventDefault();
$('#<%=btn_SearchClick.ClientID%>').click();
}
});
});

How can i store the selected tab on a RadTabStrip that can be returned to on back button click

I currently use a hidden input field that is assigned the value of the tab that has just been selected, via javascript, like so:
function onTabSelecting(sender, args) {
var tab = args.get_tab(); //get selected tab
document.getElementById("MainContent_hdnPreviousTab").value = tab.get_text(); //assign value to hidden field
if (tab.get_pageViewID()) { //ignore
tab.set_postBack(false);
}
}
I then use this assigned value when the page is returned to, on client-side (ajax) PageLoad() event:
<script type="text/javascript" language="javascript">
var runOnce = false;
function pageLoad() {
if (!runOnce) {
var lastTab = document.getElementById("<%= hdnPreviousTab.ClientID %>");
if (lastTab.value) {
if (tabStrip) {
var tab = tabStrip.findTabByText(lastTab.value);
if (tab) {
tab.click();
}
}
}
runOnce = true;
}
}
</script>
Currently in IE this works fine (I know right?), the value that was previously set in javascript is still there and i am able to lcoate the tab that the user left the page on. However in FF, Chrome, etc. i have no such luck. The hidden field is returned to it's empty state (value = "") regardless of utilising viewstate or not.
Very curious as to whether anyone has an alternative method that would be appropriate in this situation. Please let me know if this is unclear.
Many thanks.
You could use localstorage.
localStorage.setItem('tab', value);

Using Jquery to prevent a "Submit Button" from posting data if a field is left blank

So I'm putting together a little registration area for my web project, here. The user inputs various strings such as "Username", "Password", etc.
I already have a bit of code set up in order to prevent duplicate Usernames or Passwords in the database. I also have a guard in place if the "Password" and "Repeat Password" fields don't match.
What I'm trying to do now is to -
1: If the user attempts to Submit data while a field is blank, it will not post.
2: Display a "Fields cannot be blank" div I've assigned "display: none" to.
I was thinking something along the lines of assigning the input fields a class of "Required", and using some sort of code such as
if == null
.show;
return false; //To prevent the rest of the function (the submit button posting to login/register) from firing.
Running into obscene problems. Anyway. Here's what I have so far.
$("#SubmitButton").click(function () { //Click Submit
if ($("#PassReg").val() != ($("#PassConfirm").val())) { //Both fields match
$("#PasswordMismatch").show(); //Or this div shows you messed up
return false; //And nothing else fires
}
$.post("login/register", $('#ConfirmPanel *').serialize(), function (result) {
if (result == 2) //Json return from C#
$("#UsernameInUse").show(); //Shows an error div
else if (result == 3) //Json return from C#
$("#EmailInUse").show(); //Shows an error div
else {
$("#ConfirmPanel").dialog('close'); //Closes the registration dialog
}
});
});
Any thoughts? At first I thought that I literally -cannot- use "class" to mark an input field, and then have that input field compared to a null value. I don't know, though.
You should use the .submit() jquery event handler on the form instead of .click() on the button. Then return false to prevent the normal form submission if needed.
Since you are trying to submit the form using $.post you should stop the default behavior of the form submit by alwasy returning false from submit button click handler.
$("#SubmitButton").click(function () { //Click Submit
if ($("#PassReg").val() != ($("#PassConfirm").val())) { //Both fields match
$("#PasswordMismatch").show(); //Or this div shows you messed up
return false; //And nothing else fires
}
$.post("login/register", $('#ConfirmPanel *').serialize(), function (result) {
if (result == 2) //Json return from C#
$("#UsernameInUse").show(); //Shows an error div
else if (result == 3) //Json return from C#
$("#EmailInUse").show(); //Shows an error div
else {
$("#ConfirmPanel").dialog('close'); //Closes the registration dialog
}
});
return false;
});
The jQuery way of preventing form submission is to use preventDefault(), like:
$("#SubmitButton").click(function (event) { //Click Submit
if ($("#PassReg").val() != ($("#PassConfirm").val())) { //Both fields match
$("#PasswordMismatch").show(); //Or this div shows you messed up
event.preventDefault(); //And nothing else fires
return;
}
//...
});
However, since you are posting the form asynchronously when validation passes, what you really want is something more along the lines of:
$("#SubmitButton").click(function (event) { //Click Submit
event.preventDefault(); //we don't ever want to allow the default behavior
if ($("#PassReg").val() != ($("#PassConfirm").val())) { //Both fields match
$("#PasswordMismatch").show(); //Or this div shows you messed up
return;
}
//post the form
});
The rest of what you suggest (using a class to mark each required input field, checking them all for empty strings) is reasonable.
Be aware that because you are binding the button's click event instead of the form's submit event it is entirely possible for the user to submit your form without ever clicking on your button and triggering your validation code. For instance, by pressing return from any one of your text fields.
Also note that in this case you may find it more convenient to just use a traditional onsubmit directive on the form, like:
<form onsubmit="validateAndPost(); return false;">
<!-- inputs and buttons, etc. -->
</form>
<script>
function validateAndPost() {
if ($("#PassReg").val() != ($("#PassConfirm").val())) { //Both fields match
$("#PasswordMismatch").show(); //Or this div shows you messed up
return;
}
//post the form
}
</script>
Example: http://jsfiddle.net/AwxGE/
I admire your desire to use jquery, however I would advise using a normal ASP.NET ReqiredFieldValidator control. As well as making your page substantially more concise and easy to maintain, it also allows you to very simply invoke server-side validation:
public void submitbutton_click(object sender, EventArgs args){
Page.Validate();
if(Page.IsValid){
doStuff();
}
}
Please don't reinvent the wheel, and don't trust the browser to behave as you think it will.
use this -
$(document).on('click', '#SubmitButton', function () {
`enter code here`
});

jquery alertbox is getting disabled automatically

I have written the code on
ascx script:
<script src="JScripts/jquery.alerts-1.1/jquery.alerts.js" type="text/javascript"></script>
<script>
$(function() {
$('#ImageButton1').click(function() {
jAlert('Please enter a valid Suggestion ID.', 'Case Entry');
});
});
</script>
and on
Code behind:
Page.ClientScript.RegisterStartupScript(this.GetType(), "Window", "callAlert();", true);
the problem is alert box is automatically getting disabled after some time when page load fully
What could be the reason that the alert box is being disable after clicking on OK button and how to call the callAlert function in proper way.
If you are using Master page or pages then you won't get the Client Id of the button as you are declared it should be declared as $('#<%=ImageButton1.ClientID%>') or $('[id$=ImageButton1]') hope it will solve you problem.
$(document).ready(function(){
$('#<%=ImageButton1.ClientID%>').click(function() {
alert('Please enter a valid Suggestion ID.', 'Case Entry');
});
});
You can try to put the following line before the function
$(document).ready(function() {
This will make it:
$(document).ready(function() {
$('#ImageButton1').click(function() {
jAlert('Please enter a valid Suggestion ID.', 'Case Entry');
});
});
});
If you wait till the page is ready, the alert box won't be overwritten (I hope x)).
Also when you check that text box, check if the condition is false, then give the alert.
Is the condition not false? Build in a check to check if the condition is really true. If so? Redirect.
EDIT:
var answer = Confirm: ("This page will now redirect. Are you ready?")
if (answer)
//redirect
else
return
OK, so first it's important to understand that $(function(){... and $(document).ready(function() {... are equivalent, and nothing inside either will execute until the page is fully loaded. In other words, there's no need to use
Page.ClientScript.RegisterStartupScript(this.GetType(), "Window", "callAlert();", true);
That can be removed. Also, I see that you're probably using web forms. Be mindful that the Id attribute that will be rendered is not equal to the Id of the control attribute. In other words, if you have a runat="server" control with an Id of ImageButton1, using the syntax $('#ImageButton1') in your jQuery won't work.
Taking this into account, I've added an example below that uses selectors based on class attributes.
<script type="text/javascript">
$(function () {
$('.ImageButton1').click(function (e) {
var text = $('.TextBox1').val();
var redirect = true;
if (!text) {
redirect = confirm('Empty...are you sure?');
}
if (redirect) {
window.location.href = 'http://your-redirect-here.com';
}
});
});
</script>
<input class="TextBox1" type="text" />
<input class="ImageButton1" type="button" value="Click" />
That should get you where you want to go. Let me know if you have any questions.
var answer = Confirm: ("This page will now redirect. Are you ready?")
if (answer)
{
//redirect
} else
{
return false;
}
Put this after jAlert Box:
return false;
And call the function like this:
return callAlert();

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