c# - 网页文件图片/视频头

Question

在 C# 中，是否可以检测文件的网址是图像还是视频？是否有这样的标题值？

我有以下代码可以获取 Web 文件的文件大小：

System.Net.WebRequest req = System.Net.HttpWebRequest.Create("http://test.png");
req.Method = "HEAD";
using (System.Net.WebResponse resp = req.GetResponse())
{
    int ContentLength;
    if(int.TryParse(resp.Headers.Get("Content-Length"), out ContentLength))
    { 
        //Do something useful with ContentLength here 
    }
}

可以修改此代码以查看文件是图像还是视频？

提前致谢

Answer 1

You can check resp.Headers.Get("Content-Type") in response header.

For example, it will be image/jpeg for jpg file.

See list of available content types.

Answer 2

What you're looking for is the "Content-Type" header

string uri = "http://assets3.parliament.uk/iv/main-large//ImageVault/Images/id_7382/scope_0/ImageVaultHandler.aspx.jpg";
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
request.Method = "HEAD";

using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
    var contentType = response.Headers["Content-Type"];

    Console.WriteLine(contentType);
}