使用 C# 和 wcf 防止 Firefox 中缓存的 HTTP 标头

发布于 2024-12-09 21:33:58 字数 1704 浏览 0 评论 0原文

我有一个提供图像的 wcf 服务，这些图像是不稳定的并且定期更新。我使用 img 标签将它们显示在网页上，

<img src="location/map/image/{coordinates}

坐标是一个数字，例如 12786。在我的 javascript 中，我在不同时间创建和删除图像标签。我使用以下代码添加 HTTP 标头以防止缓存

    //whatever the result we will not cache this at the client or intermediate proxies
    HttpContext.Current.Response.ClearHeaders();
    HttpContext.Current.Response.AppendHeader("Cache-Control", "no-cache"); //HTTP 1.1
    HttpContext.Current.Response.AppendHeader("Cache-Control", "private"); // HTTP 1.1
    HttpContext.Current.Response.AppendHeader("Cache-Control", "no-store"); // HTTP 1.1
    HttpContext.Current.Response.AppendHeader("Cache-Control", "must-revalidate"); // HTTP 1.1
    HttpContext.Current.Response.AppendHeader("Cache-Control", "max-stale=0"); // HTTP 1.1 
    HttpContext.Current.Response.AppendHeader("Cache-Control", "post-check=0"); // HTTP 1.1 
    HttpContext.Current.Response.AppendHeader("Cache-Control", "pre-check=0"); // HTTP 1.1 
    HttpContext.Current.Response.AppendHeader("Pragma", "no-cache"); // HTTP 1.1 
    HttpContext.Current.Response.AppendHeader("Keep-Alive", "timeout=3, max=993"); // HTTP 1.1 
    HttpContext.Current.Response.AppendHeader("Expires", "Mon, 26 Jul 1997 05:00:00 GMT"); // HTTP 1.1 
    //write the image http response

我注意到在 Firefox 中图像永远不会刷新并诉诸于添加虚拟查询字符串参数。我了解到 firefox DOM 会注意到图像 url 之前已在同一页面上使用过，并且不会刷新它。

这似乎完全违背了 Http(REST)，因为图像无论如何都没有链接到文档，并且是一个单独的 HTTP 资源，为什么它的可访问性应该由引用它的页面/DOM 来确定。

这完全违背了 HTTP。

我的问题是；有没有办法在 Firefox 中使用 HTTP 来防止这种行为？请不要说 Response.HttpContext.Current.Response.Cache.SetCacheability(HttpCacheability.NoCache); 它在 FF 上不起作用。

我用的是FF6

原文

I have a wcf service serving images, these images are volatile and regularly updated. I display them on a webpage using an img tag

<img src="location/map/image/{coordinates}

cordinates is a number e.g. 12786.
In my javascript I create and remove the image tag at different times. I have used the following code to add HTTP headers to prevent caching

    //whatever the result we will not cache this at the client or intermediate proxies
    HttpContext.Current.Response.ClearHeaders();
    HttpContext.Current.Response.AppendHeader("Cache-Control", "no-cache"); //HTTP 1.1
    HttpContext.Current.Response.AppendHeader("Cache-Control", "private"); // HTTP 1.1
    HttpContext.Current.Response.AppendHeader("Cache-Control", "no-store"); // HTTP 1.1
    HttpContext.Current.Response.AppendHeader("Cache-Control", "must-revalidate"); // HTTP 1.1
    HttpContext.Current.Response.AppendHeader("Cache-Control", "max-stale=0"); // HTTP 1.1 
    HttpContext.Current.Response.AppendHeader("Cache-Control", "post-check=0"); // HTTP 1.1 
    HttpContext.Current.Response.AppendHeader("Cache-Control", "pre-check=0"); // HTTP 1.1 
    HttpContext.Current.Response.AppendHeader("Pragma", "no-cache"); // HTTP 1.1 
    HttpContext.Current.Response.AppendHeader("Keep-Alive", "timeout=3, max=993"); // HTTP 1.1 
    HttpContext.Current.Response.AppendHeader("Expires", "Mon, 26 Jul 1997 05:00:00 GMT"); // HTTP 1.1 
    //write the image http response

I have noticed that in firefox the image is never refeshed and resorted to adding a dummy query string parameter. I have come to understand that firefox DOM will notice that the image url has been used before on the same page and won't refresh it.

This seems to be completely against Http(REST) since the image is not linked to the document in anyway and is a seperate HTTP resource why should it's accessibility be determined by the page/DOM it is referrenced in.

This is completely against HTTP.

My question is; is there a way of preventing this behaviour in firefox using HTTP? Please don't say Response.HttpContext.Current.Response.Cache.SetCacheability(HttpCacheability.NoCache); it doesn't work on FF.

I am using FF6.

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从此见与不见 2024-12-16 21:33:58

尝试添加以下内容：

HttpContext.Current.Response.AppendHeader("Pragma", "no-cache"); 
HttpContext.Current.Response.AppendHeader("Cache-Control", "no-cache");

HttpContext.Current.Response.CacheControl = "no-cache"; 
HttpContext.Current.Response.Expires = -1;

HttpContext.Current.response.ExpiresAbsolute = new DateTime(1900, 1, 1); 
HttpContext.Current.response.Cache.SetCacheability(HttpCacheability.NoCache);

Try adding the following:

HttpContext.Current.Response.AppendHeader("Pragma", "no-cache"); 
HttpContext.Current.Response.AppendHeader("Cache-Control", "no-cache");

HttpContext.Current.Response.CacheControl = "no-cache"; 
HttpContext.Current.Response.Expires = -1;

HttpContext.Current.response.ExpiresAbsolute = new DateTime(1900, 1, 1); 
HttpContext.Current.response.Cache.SetCacheability(HttpCacheability.NoCache);

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