我正在用PHP做一个在线测试应用程序。我想限制用户在考试中返回。
我尝试了下面的脚本，但它停止了我的计时器。
我该怎么办?
定时器存储在cdtimer.js文件中。
<script type="text/javascript">
window.history.forward();
function noBack()
{
window.history.forward();
}
</script>
<body onLoad="noBack();" onpageshow="if (event.persisted) noBack();" onUnload="">
我有一个考试计时器，它从一个MySQL值中获取考试的持续时间。计时器随之启动，但当我输入禁用后退按钮的代码时，它就停止了。我有什么问题?
当前回答
<script>
window.location.hash = "no-back-button";
// Again because Google Chrome doesn't insert
// the first hash into the history
window.location.hash = "Again-No-back-button";
window.onhashchange = function(){
window.location.hash = "no-back-button";
}
</script>
其他回答
这就是我实现它的方法。
奇怪的是，换窗口。在谷歌Chrome和Safari浏览器中，location无法正常工作。
它发生在那个位置。hash不会在Chrome和Safari的历史记录中创建条目。所以你必须使用推力器。
这在所有浏览器中都适用。
history.pushState({ page: 1 }, "title 1", "#nbb");
window.onhashchange = function (event) {
window.location.hash = "nbb";
};
在现代浏览器中，这似乎是可行的:
// https://developer.mozilla.org/en-US/docs/Web/API/History_API
let popHandler = () => {
if (confirm('Go back?')) {
window.history.back()
} else {
window.history.forward()
setTimeout(() => {
window.addEventListener('popstate', popHandler, {once: true})
}, 50) // delay needed since the above is an async operation for some reason
}
}
window.addEventListener('popstate', popHandler, {once: true})
window.history.pushState(null,null,null)
只需设置location.hash="Something"。在按下返回按钮时，散列将从URL中删除，但页面不会返回。
此方法用于防止意外返回，但出于安全性考虑，您应该设计用于防止应答的后端。
有很多原因可以解释为什么禁用后退按钮实际上不起作用。最好的办法是警告用户:
window.onbeforeunload = function() { return "Your work will be lost."; };
本页确实列出了一些禁用后退按钮的方法，但都不保证:
http://www.irt.org/script/311.htm
我遇到了这个问题，需要一个在各种浏览器上正确工作的解决方案，包括Mobile Safari(在发布时是iOS 9)。没有一个解决方案是完全正确的。我提供以下建议(在Internet Explorer 11、Firefox、Chrome和Safari上进行了测试):
history.pushState(null, document.title, location.href);
window.addEventListener('popstate', function (event)
{
history.pushState(null, document.title, location.href);
});
注意事项:
history.forward() (my old solution) does not work on Mobile Safari --- it seems to do nothing (i.e., the user can still go back). history.pushState() does work on all of them. the third argument to history.pushState() is a url. Solutions which pass a string like 'no-back-button' or 'pagename' seem to work OK, until you then try a Refresh/Reload on the page, at which point a "Page not found" error is generated when the browser tries to locate a page with that as its URL. (The browser is also likely to include that string in the address bar when on the page, which is ugly.) location.href should be used for the URL. the second argument to history.pushState() is a title. Looking around the web most places say it is "not used", and all the solutions here pass null for that. However, in Mobile Safari at least, that puts the page's URL into the history dropdown the user can access. But when it adds an entry for a page visit normally, it puts in its title, which is preferable. So passing document.title for that results in the same behaviour.
