C# Read file info from URL

asp.net, c#, file, url

Solution

Assuming your HTTP Server allows this.

System.Net.WebRequest req = System.Net.HttpWebRequest.Create("http:\\your\url.ext");
req.Method = "HEAD";
using (System.Net.WebResponse resp = req.GetResponse())
{
    DateTime LastModified;
    if(DateTime.TryParse(resp.Headers.Get("Last-Modified"), out LastModified))
    { 
        //Check if date is good and then go to full download method.
    }
}

When this method doesn't work because the server doesn't allow it. Then the only way of doing this is by fully downloading the file.

Problem

In my ASP.NET MVC application I'm reading an external file from URL and saving it into a directory on my server. I do this in a loop for every few seconds to have actual data if the file was modified. What I need is to recognize that the `LastWrittenTime` of the file accessed via the URL is different from file already downloaded to the server. I cannot use `FileInfo` class because "URI formats are not supported". So how do I get the last written time of the file from the URL without needing to download the full file for every loop?

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