Develop Reference

Disable print screen option in IE,but the code works fine with google chrome

Print screen option has been disabled in Google Chrome with the below js code.
document.onkeydown = keydown;
document.onkeyup = keyup;
function keydown(e) {
console.log("key down triggered");
var keystroke = String.fromCharCode(event.keyCode).toLowerCase();
if (e.keyCode == 44 || e.keyCode == "44" || e.which == 44 || e.which == "44") {
e.cancelBubble = true;
e.preventDefault();
e.stopImmediatePropagation();
}
if (e.ctrlKey && (e.key == "P" || e.key == "C" || e.key == "A" || e.key == "p"||e.key == "c" || e.key == "a" || e.charCode == 16 || e.charCode == 112 ||e.keyCode == 80) || (e.keyCode == 44) || (e.keyCode == 123)) {
//alert("Inspect element & Print &cut/copy option is restricted");
e.cancelBubble = true;
e.preventDefault();
e.stopImmediatePropagation();
}
if (e.keyCode > 111 && e.keyCode < 124) {
//alert("Function option is restricted");
e.cancelBubble = true;
e.preventDefault();
e.stopImmediatePropagation();
}
if (e.key == "F11" || e.key == "f11") {
//alert("Function option is restricted");
e.cancelBubble = true;
e.preventDefault();
e.stopImmediatePropagation();
}
}
function keyup(e) {
debugger;
console.log("key up triggered");
if (e.keyCode == 44 || e.keyCode == "44" || e.which == 44 || e.which =="44") {
e.cancelBubble = true;
e.preventDefault();
e.stopImmediatePropagation();
}
if (e.keyCode > 111 && e.keyCode < 124) {
e.cancelBubble = true;
e.preventDefault();
e.stopImmediatePropagation();
}
if (e.key == "F11" || e.key == "f11") {
//alert("Function option is restricted");
e.cancelBubble = true;
e.preventDefault();
e.stopImmediatePropagation();
}
The above code works fine in Google Chrome.key code 44 for Print screen option is used.In IE all the function keys have been restricted,but the keyup and keydown function is not getting triggered,when in IE browser alone.
What is the alternate way to handle print screen option in IE Browser using jquery.?
And additionally the above code fails to prevent print screen when the user opens a bootbox alert pop up inside a web application.
Suggest a solution for the above 2 scenarios.

Don't.
No matter how clever your code, you can't stop me from focussing a different window on my second monitor and hitting Print Screen there to get a copy of whatever's on-screen that you're trying to stop me from screenshotting.
Or I could just open the browser console (even if you block F12 / Ctrl+Shift+I, I can still get there via the browser's menus) and type document.onkeydown = document.onkeyup = null; and break your entire guard.
It's not often that I "answer" a question by completely shutting it down, but you are wasting your time.

How to disable Ctrl+U using Javascript

I just want to disable Ctrl+U and Ctrl+C event. The primary purpose of doing this is, preventing users from downloading any image or copying content from my website easily i.e. pressing Ctrl+U for viewing my webpage's source code or pressing Ctrl+C for copying content directly from my webpage.
Currently, I am using this piece of code but it disables my entire keyboard
<script>
/*function check(e)
{
alert(e.keyCode);
}*/
document.onkeydown = function(e) {
if (e.ctrlKey && (e.keyCode === 67 || e.keyCode === 86 || e.keyCode === 85 || e.keyCode === 117)) {//Alt+c, Alt+v will also be disabled sadly.
alert('not allowed');
}
return false;
};
</script>

Your problem is the return statement.
Though I would suggest you use addEventListener and the like, this is a working copy of your code:
document.onkeydown = function(e) {
if (e.ctrlKey &&
(e.keyCode === 67 ||
e.keyCode === 86 ||
e.keyCode === 85 ||
e.keyCode === 117)) {
alert('not allowed');
return false;
} else {
return true;
}
};

This is finally what I got to disable Ctrl+U:
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<script>
document.onkeydown = function(e) {
if (e.ctrlKey &&
(e.keyCode === 67 ||
e.keyCode === 86 ||
e.keyCode === 85 ||
e.keyCode === 117)) {
return false;
} else {
return true;
}
};
$(document).keypress("u",function(e) {
if(e.ctrlKey)
{
return false;
}
else
{
return true;
}
});
</script>

Its simple just use the following code it will disable only Ctrl+U while Ctrl+C, Ctrl+V, Ctrl+S etc will works fine:
<script>
document.onkeydown = function(e) {
if (e.ctrlKey &&
(e.keyCode === 85 )) {
return false;
}
};
</script>

try check this link from jsfiddle.
js
shortcut.add("Ctrl+U",function(){
alert('Sorry\nNo CTRL+U is allowed. Be creative!')
}),
it will simple show and error when you try to hit Ctrl+U on your keybord
But check the link, there is alot of code

To disable right click
document.addEventListener('contextmenu', event => event.preventDefault());
To disable F12 options
document.onkeypress = function (event) {
event = (event || window.event);
if (event.keyCode == 123) {
return false;
}
}
document.onmousedown = function (event) {
event = (event || window.event);
if (event.keyCode == 123) {
return false;
}
}
document.onkeydown = function (event) {
event = (event || window.event);
if (event.keyCode == 123) {
return false;
}
}
To Disable ctrl+c, ctrl+u
jQuery(document).ready(function($){
$(document).keydown(function(event) {
var pressedKey = String.fromCharCode(event.keyCode).toLowerCase();
if (event.ctrlKey && (pressedKey == "c" || pressedKey == "u")) {
alert('Sorry, This Functionality Has Been Disabled!');
//disable key press porcessing
return false;
}
});
});

This will Disable Ctrl + U and Right-click (make sure it's at the top of all your code) :
<!-- Disable CTRL U and Right Click -->
<script>
document.onkeydown = function(e) {
if (e.ctrlKey && e.keyCode === 85) {
return false;
}
};
</script>
<body oncontextmenu="return false;"></body>
<!-- disable CTRL U and Right Click -->

you can use the below script
<script>
/*function check(e)
{
alert(e.keyCode);
}*/
document.onkeydown = function(e) {
if (e.ctrlKey && (e.keyCode === 67 || e.keyCode === 86 || e.keyCode === 85 || e.keyCode === 117 || e.keycode === 17 || e.keycode === 85)) {//ctrl+u Alt+c, Alt+v will also be disabled sadly.
alert('not allowed');
}
return false;
};
</script>

Its simple just use the following code it will disable only Ctrl+U while Ctrl+C, Ctrl+V, Ctrl+S etc will works fine: but it will disable your page source too.
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.0/jquery.min.js" type="text/javascript"></script>
<script type="text/javascript" language="javascript"> $(function () { $(this).bind("contextmenu", function (e) { e.preventDefault(); }); }); </script>
<script>
document.onkeydown = function(e) {
if (e.ctrlKey &&
(e.keyCode === 85 )) {
return false;
}
};
</script>

Block F5 key using JavaScript

I have written some code to block the F5 key on web page. It's working fine except when I have to display a large amount of data. If you press the F5 key during the loading duration in which the HTML and JavaScript code is generated, my page gets refreshed.
Here is the code that I am using to block the F5 key:
document.onkeydown = fn;
var fn = function (e){
if (!e)
var e = window.event;
var keycode = e.keyCode;
if (e.which)
keycode = e.which;
var src = e.srcElement;
if (e.target)
src = e.target;
// 116 = F5
if (116 == keycode) {
// Firefox and other non IE browsers
if (e.preventDefault) {
e.preventDefault();
e.stopPropagation();
// Internet Explorer
}else if (e.keyCode){
e.keyCode = 0;
e.returnValue = false;
e.cancelBubble = true;
}
return false;
}
});
I think this code is not working when the HTML and JavaScript code is generating.

I have some very simple code for preventing F5 that I use myself. Works in IE, Chrome and Firefox:
function disableButtonsDown(e) {
if ((e.which || e.keyCode) == 116) e.preventDefault();
};
$(document).on("keydown", disableButtonsDown);

document.onkeydown=disableF5;
var version = navigator.appVersion;
function disableF5(e)
{ var keycode = (window.event) ? event.keyCode : e.keyCode;
if ((version.indexOf('MSIE') != -1))
{ if (keycode == 116)
{ event.keyCode = 0;
event.returnValue = false;
return false;
}
}
else
{ if (keycode == 116)
return false;
}
}

Bind ctrl + u keystroke in jQuery

I am trying to build a hotkey into my web application in jQuery. I am trying to bind the Ctrl+U key stroke. Here is what I have:
$(document).keypress(function(e) {
if(e.ctrlKey && e.which == 117) {
if($("#nav-user-details").length > 0) {
$("#nav-user-details").find(".dropdown-menu").toggle();
}
}
});
This is not working though. How do I bind this key strokes?
Thanks.

Try this please http://jsfiddle.net/TN7GZ/
Press Ctrl+U and the screen will alert.
This will fit your need :)
Code
var isCtrl = false;
document.onkeyup=function(e){
if(e.which == 17) isCtrl=false;
}
document.onkeydown=function(e){
if(e.which == 17) isCtrl=true;
if(e.which == 85 && isCtrl == true) {
//run code for CTRL+U -- ie, whatever!
alert('CTRL + U stuff');
return false;
}
}
​

I’m pretty sure 85 is the keycode for u, or am I missing something?
If you want mac support as well (the command key), it can get messy. I wrote a snippet before that might help you, but it involves browser detections (yuck):
var cmd = false;
$(document).on('keydown', function(e) {
if(detectMacCommand(e.which)) {
cmd = true;
return;
}
// now detect print (ctr/cmd + p)
if ( e.which == 85 && ( e.ctrl || cmd ) ) {
e.preventDefault();
alert('ctrl/cmd + u');
}
}).on('keyup', function(e) {
if(detectMacCommand(e.which)) {
cmd = false;
return;
}
});
function detectMacCommand(key) {
return ( $.browser.mozilla && key == 224 ||
$.browser.opera && key == 17 ||
$.browser.webkit && ( key == 91 || key == 93 ));
}
Demo: http://jsbin.com/afijam/2

$(document).keypress("u",function(e) {
if(e.ctrlKey)
alert("Ctrl+U was pressed!!");
});

You'll have to use keydown instead of keypress. Keypress does not trigger for non-char keys.
$(document).keydown(function (e) {
if (e.ctrlKey && e.which === 81) {
alert("key pressed");
return false;
}
});

Try this:
var prevKey = null;
$(document).keydown(function (e) {
var thisKey = e.which;
if (prevKey && prevKey == 17) {
if (thisKey == 85) {
// Your code.
}
}
prevKey = thisKey;
});

If you are working in a Xhtml file and you get an error The entity must immediately follow the & then you should use &&& instead of &&.

Event is not defined error in javascript only Firefox

I use the following script to validate the text box to enter only numbers and (.) which means it is decimal textbox validation. It was work fine in Internet Explorer and Google Chrome. If I execute the function in FireFox I get the following Error:
Event Is not Defined.
How to solve this?
function abc(event) {
if (event.keyCode > 47 && event.keyCode < 58) {
return true;
}
if (event.keyCode == 8 || event.keyCode == 46)
{
return true;
}
return false;
}
I call this function like this:
$('.decimalValidate').live('keypress',function(){
var decimalid=$(this).attr("id");
var decimalval=$('#'+decimalid).val();
var decimalvalidate=abc(decimalval);
if(decimalvalidate == false)
return false;
});
I assign this validation for text box like this:
input type="text" id="Total" class="abc"

Try this
function abc(event) {
if(!event)
event= window.event;
if (event.keyCode > 47 && event.keyCode < 58) {
return true;
}
if (event.keyCode == 8 || event.keyCode == 46)
{
return true;
}
return false;
}
and
$('.decimalValidate').live('keypress',function(e){
var decimalid=$(this).attr("id");
var decimalval=$('#'+decimalid).val();
var decimalvalidate=abc(evt); //keypress event
if(decimalvalidate == false)
return false;
});

decimalval is not an Event object, and you have to pass it to the abc function in ordert to find out which key you pressed:
$('.decimalValidate').live('keypress',function(ev){
var decimalid=$(this).attr("id");
var decimalval=$('#'+decimalid).val();
var decimalvalidate=abc(ev);
if(decimalvalidate == false)
return false;
});

$('.decimalValidate').live('keypress',function(e){
var decimalvalidate=abc(e); //this will point to the event of the keypress.
if(decimalvalidate == false)
return false;
});
I am not sure why you did all of the decimalid and decimalval operations, but if you want the event, do as I wrote in the edited code above.
Good luck.

$('.decimalValidate').on('keypress',function(event){
var decimalid = $(this).attr("id");
var decimalval = $('#'+decimalid).val();
var decimalvalidate = abc(event);
if(decimalvalidate == false)
return false;
});
function abc(event) {
if (event.keyCode > 47 && event.keyCode < 58) {
return true;
}
if (event.keyCode == 8 || event.keyCode == 46)
{
return true;
}
return false;
}
It helps you..