WebRequest.Create（“ URL”）的可能方式总是失败？

Question

Currently in my website, I need to verify a URL param to ensure that it's a valid and it's an accessible URL. I'm using the code below:

 var request = WebRequest.Create(url) as HttpWebRequest;
 if (request == null) return false;
     request.Method = "HEAD";
     using (var response = (HttpWebResponse)request.GetResponse())
     {
         return response.StatusCode == HttpStatusCode.OK;
     }

I had deployed the website in my server and so far every work fine, no issue with the URL verification.

Now I had published the same application in client server. But the URL verification always failed even just for http://www.google.com . I have log file that record the failure of verification and the value.

I retrieve all those URL value in client site and test again in my own server but no issue at all.

That's why I suspect that it's not code issue but environment issue.

Any advice on what to check?

Thanks

Answer 1

Try the following. If there is an exception, hopefully it will give you a clue on the issue you are having.

var request = WebRequest.Create(url) as HttpWebRequest;
if (request == null) return false;
 request.AllowRedirect = false;  // default: true
 request.Method = "GET";   // this is the default

 try
  {
    var response = (HttpWebResponse)request.GetResponse());
    if (res.StatusCode == HttpStatusCode.OK)
        return true;
    else
       return false;
  }
 catch (Exception ex)
  {
     return ex.Message;
  }