如何检查是否浏览器缓存禁用 [英] How to check if browser caching disabled

问题描述

有没有Javascript或C＃的方式来告诉浏览器是否有人在使用已禁用的静态内容缓存？

Is there a way in either Javascript or C# to tell if the browser that someone is using has disabled caching of static content?

我需要能够测试浏览器是否缓存了优化。

I need to be able to test whether or not the browser is optimized for caching.

推荐答案

更新

我做的问题多一点调查，你可以找到更详细的答案在我最近的帖子
注意，以下描述的溶液（最初）不是跨浏览器溶液

I did a bit more investigation of the problem and you can find more detailed answer in my recent post Note, the solution described below (initially) is not cross browser solution.

不知道是否有帮助，但你可以试试下面的技巧：
1.添加一些资源给你页面，让我们说这将是JavaScript文件 cachedetect.js 。
2.服务器应生成 cachedetect.js 每次有人提出要求。它应该包含在响应缓存相关的头，也就是说，如果浏览器的缓存被启用，应缓存很长一段时间的资源。每个 cachedetect.js 应该是这样的：

Not sure if it helps, but you can try the following trick: 1. Add some resource to you page, let's say it will be javascript file cachedetect.js. 2. The server should generate cachedetect.js each time someone request it. And it should contain cache-related headers in response, i.e. if browser's cache is enabled the resource should be cached for long time. Each cachedetect.js should look like this:

var version = [incrementally generated number here];
var cacheEnabled; //will contain the result of our check
var cloneCallback;//function which will compare versions from two javascript files

function isCacheEnabled(){
   if(!window.cloneCallback){
       var currentVersion = version;//cache current version of the file
       // request the same cachedetect.js by adding <script> tag dynamically to <header>
       var head = document.getElementsByTagName("head")[0];
       var script = document.createElement('script');
       script.type = 'text/javascript';
       script.src = "cachedetect.js";
       // newly loaded cachedetect.js will execute the same function isCacheEnabled, so we need to prevent it from loading the script for third time by checking for cloneCallback existence       
       cloneCallback = function(){
           // once file will be loaded, version variable will contain different from currentVersion value in case when cache is disabled 
           window.cacheEnabled = currentVersion == window.version;        
       };      
       head.appendChild(script);

    }  else {
        window.cloneCallback();
    }   
}

isCacheEnabled();

之后，你可以简单地检查 cacheEnabled ===真正或 cacheEnabled ===虚假一段时间后，时间。

这篇关于如何检查是否浏览器缓存禁用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！