C＃如何从URL获取服务器错误？

Question

We have a url and we need to check whether web page is active or not. We tried following code: WebResponse objResponse = null;

        WebRequest objRequest = HttpWebRequest.Create(URL);
        objRequest.Method = "HEAD";
        try
        {
            objResponse = objRequest.GetResponse();
            objResponse.Close();                
        }
        catch (Exception ex)
        {

        }

Above code gave exception if unable to get a response but also works fine even if we have a "server error" on that page? Any help how to get server error?

Answer 1

The HttpResponse class has a StatusCode property which you can check. If it's 200 everything is ok.

You can change your code to this:

        HttpWebResponse objResponse = null;
        var objRequest = HttpWebRequest.Create("http://google.com"); 
        objResponse = (HttpWebResponse) objRequest.GetResponse();
        if(objResponse.StatusCode != HttpStatusCode.OK)
        {
            Console.WriteLine("It failed");
        }else{
            Console.WriteLine("It worked");
        }

Answer 2

For one thing, use a using statement on the response - that way you'll dispose of it whatever happens.

Now, if a WebException is thrown, you can catch that and look at WebException.Response to find out the status code and any data sent back:

WebRequest request = WebRequest.Create(URL);
request.Method = "HEAD";
try
{
    using (WebResponse response = request.GetResponse())
    {
        // Use data for success case
    }
}
catch (WebException ex)
{
    HttpWebResponse errorResponse = (HttpWebResponse) ex.Response;
    HttpStatusCode status = errorResponse.StatusCode;
    // etc
}