如何使Javascript警报显示只有一次，永远？ [英] How do I make a Javascript alert display only once, ever?

问题描述

我可怕的Javascript，但不幸的是，我需要这一个任务完成。我需要一个Javascript警报，只显示一次 - 每次浏览器会话一次，但只有一次。我正在做一个学校比赛的项目;该警报将涉及Internet Explorer与我的网站不兼容的方式，建议使用Chrome或Firefox。然而，我不想用弹出窗口来评判裁判，所以它只出现一次是最好的。我发现在线下面显示的代码，但我不能使它正常工作。它可能是一些简单的括号缺少某处 - 再次，我不好用的JavaScript，只是HTML和CSS。 ：P如果鼓励替代代码执行我的请求，那么一切方式，建议吧！感谢所有！

 < script src =http://code.jquery.com/jquery-1.10.1。 min.js>< / script> 
 
<！ -  [if IE]> 
< script type =text / javascript> 
 $（document）.one（function（）{alert（您正在使用Internet Explorer查看此网页。在使用Internet Explorer时，您的体验可能不佳;我们建议使用其他互联网浏览器Firefox，查看我们的网站。）;}）; 
< / script> 
<！[endif]  - > 
  

解决方案

$ c>不是你需要的，因为页面刷新将覆盖所有的'内存'。

你最有可能寻找 localStorage 或者，如果您在版本8之前使用Internet Explorer，请使用Cookie：

 < script type = text / javascript> 
 var alerts = localStorage.getItem（'remind'）|| ''; 
 if（alerts！='yes'）{
 alert（您正在使用Internet Explorer查看此网页。使用Internet Explorer时，您的体验可能不佳;我们建议使用其他互联网浏览器如Chrome或Firefox，查看我们的网站。 
 localStorage.setItem（'remind'，'yes'）; 
} 
< / script> 
   
 
 
 
 编辑：
 
 
 
对于8之前的IE版本，您需要使用Cookie，因为不支持 localStorage 。这是完全相同的概念，只是不同的方法。请查看此问题以实施
 
 
 
在您复制了示例，您应该有两个函数 -   createCookie（）和 getCookie（）。
  var createCookie = function（name，value，days）{
 .... 
 //从其他问题中复制它
 .. 
} 
 
 function getCookie（c_name）{
 .... 
 //从另一个问题中复制它
 .. 
} 
 
<！ -  [if IE] 
< script type =text / javascript> 
 var remind = getCookie（'remind'）|| ''; 
 if（alerts！='yes'）{
 alert（您正在使用Internet Explorer查看此网页。使用Internet Explorer时，您的体验可能不佳;我们建议使用其他互联网浏览器如Chrome或Firefox，查看我们的网站。 
 createCookie（'remind'，'yes'，365）; // cookie expires after 365 days 
} 
< / script> 
<！[endif]  - > 
  
希望这有助于！
 
I'm terrible at Javascript, but unfortunately, I need this one task completed.  I need a Javascript alert to only display once--not once per browser session, but only once ever.  I'm working on a project for a school competition; the alert will pertain to how Internet Explorer isn't compatible with my site and Chrome or Firefox is recommended.  However, I don't want to pester the judges with pop-ups, so it only appearing up once would be best.  I found the code that's displayed below online, but I can't make it work correctly.  It may be something as simple as a parenthesis missing somewhere--again, I'm not good with Javascript, just HTML and CSS.  :P  If alternative code is encouraged to carry out my request, then by all means, suggest it!  Thanks to all!
<script src="http://code.jquery.com/jquery-1.10.1.min.js"></script>

<!--[if IE]>    
    <script type="text/javascript">
        $(document).one(function() { alert("You are using Internet Explorer to view this webpage.  Your experience may be subpar while using Internet Explorer; we recommend using an alternative internet browser, such as Chrome or Firefox, to view our website."); } );
    </script>
<![endif]-->

解决方案
one is NOT what you need as a page refresh will override all the 'memory'.

You are most likely looking for localStorage or, if you are using internet explorer prior to version 8, use cookies:
    <script type="text/javascript">
        var alerted = localStorage.getItem('alerted') || '';
        if (alerted != 'yes') {
         alert("You are using Internet Explorer to view this webpage.  Your experience may be subpar while using Internet Explorer; we recommend using an alternative internet browser, such as Chrome or Firefox, to view our website.");
         localStorage.setItem('alerted','yes');
        }
    </script>
EDIT:

For IE versions prior to 8 you need to use cookies, since there is not suppor for localStorage. It's the exact same concept, just different methods. Take a look at this question for implementing cookies on your page.

After you copied the code from the example, you should have 2 functions - createCookie() and getCookie().
var createCookie = function(name, value, days) {
....
//copy it from the other question
..
}

function getCookie(c_name) {
....
//copy it from the other question
..
}

<!--[if IE]>  
    <script type="text/javascript">
                var alerted = getCookie('alerted') || '';
                if (alerted != 'yes') {
                 alert("You are using Internet Explorer to view this webpage.  Your experience may be subpar while using Internet Explorer; we recommend using an alternative internet browser, such as Chrome or Firefox, to view our website.");
                 createCookie('alerted','yes',365);//cookies expires after 365 days
                }
            </script>
<![endif]-->
Hope this helps!

                        
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