Question

WebRequest request = WebRequest.Create(new Uri("http://istr03.izlesene.com/data/videos/7213/7213704-360_2-103k.mp4/e5ae7a74a30f645c6fc0c5aa0fde9076/531B29B7"));
request.Method = "HEAD";
using (WebResponse response = request.GetResponse()) {
    double boyut = response.ContentLength / 1024 / 1024;
    string tip = response.ContentType;
}

此代码适用于其他网站，但对于此网址，会引发异常; （500）内部服务器错误。

代码对此网址失败可能有什么不同？

Answer 1

您需要设置User-Agent http header。这个特定的服务器希望可能会嗅探客户端的功能。

调整代码以获取HttpWebRequest并设置UserAgent属性：

        var request = (HttpWebRequest) WebRequest.Create(
             new Uri("http://your url here"));
        request.Method = "HEAD";
        request.UserAgent = "spider/1.0"; 

        using (WebResponse response = request.GetResponse())
        {
            double boyut = response.ContentLength / 1024 / 1024;
            string tip = response.ContentType;
        }

您网址的内容长度为：13381446
内容类型是：video / mp4

Answer 2

我确实用fiddler看看发生了什么。您提供的网址已重定向到另一个URL。

HEAD http://istr03.izlesene.com/data/videos/7213/7213704-360_2-103k.mp4/e5ae7a74a30f645c6fc0c5aa0fde9076/531B29B7 HTTP/1.1
User-Agent: Fiddler
Host: istr03.izlesene.com

HTTP/1.1 302 Moved Temporarily
Via: 1.1 81.212.99.207 (McAfee Web Gateway 7.3.2.3.0.16052)
Date: Fri, 07 Mar 2014 14:45:20 GMT
Server: nginx/1.4.4
Location: http://sstr06.izlesene.com/data/videos/7213/7213704-360_2-103k.mp4?token=WCk3CCIxJYVC0ESMOs1cFw&ts=1394210720
Connection: Keep-Alive
Content-Type: text/html
Content-Length: 160

因此，您需要从第一个响应中解析位置，并使用HEAD方法向服务器执行另一个请求，您将获得视频的内容长度。

HEAD http://sstr06.izlesene.com/data/videos/7213/7213704-360_2-103k.mp4?token=WCk3CCIxJYVC0ESMOs1cFw&ts=1394210720 HTTP/1.1
User-Agent: Fiddler
Host: sstr06.izlesene.com

HTTP/1.1 200 OK
Via: 1.1 81.212.99.207 (McAfee Web Gateway 7.3.2.3.0.16052)
Date: Fri, 07 Mar 2014 14:45:21 GMT
ETag: "53037f98-cc2f46"
Server: nginx/1.4.4
Connection: Keep-Alive
Content-Type: video/mp4
Accept-Ranges: bytes
Last-Modified: Tue, 18 Feb 2014 15:43:20 GMT
Content-Length: 13381446

WebRequest无法检索视频信息？

2 个答案: