使用ETag添加IHttpModule

Question

我写了一个简单的IHttpModule

void context_PreSendRequestHeaders(object sender, EventArgs e)
{
    //remove default
    HttpContext.Current.Response.Headers.Remove("ETag");

    //add version one
    HttpContext.Current.Response.Headers.Add("ETag", "Test1.0");
}

如果我想删除IIS，并添加自己的ETag来控制来自客户端的javascript和css文件请求--就像我想要的更新一样，它将被自动刷新。客户端对ETag的响应正常

如果-无-匹配:Test1.0if-修改-自:星期一，2014年6月2日11:08:54格林尼治时间

但是IIS总是返回内容而不是304

Answer 1

void context_PreSendRequestHeaders(object sender, EventArgs e)
    {
        var etag = "Test4-0";

        //remove default
        HttpContext.Current.Response.Headers.Remove("ETag");

        //add version one
        HttpContext.Current.Response.Headers.Add("ETag", etag);

        string ifNoneMatch = HttpContext.Current.Request.Headers["If-None-Match"];
        Debug.WriteLine(String.Format("ifNoneMatch - {0}", ifNoneMatch));

        if (ifNoneMatch != null && ifNoneMatch.Contains(","))
        {
            ifNoneMatch = ifNoneMatch.Substring(0, ifNoneMatch.IndexOf(",", StringComparison.Ordinal));
        }

        HttpContext.Current.Response.Cache.VaryByHeaders["If-None-Match"] = true;
        Debug.WriteLine(String.Format("ifNoneMatch - etag: {0}-{1}", ifNoneMatch, etag));
        if (etag == ifNoneMatch)
        {
            Debug.WriteLine(String.Format("ifNoneMatch2 - etag: {0}-{1}", ifNoneMatch, etag));
            HttpContext.Current.Response.ClearContent();
            HttpContext.Current.Response.StatusCode = (int)HttpStatusCode.NotModified;
            HttpContext.Current.Response.SuppressContent = true;
        }
    }
}