C#：当网页没有响应时，退出 System.Net.WebClient 下载（无论如何）

Question

If the website isn't responding after one second or so, it's probably safe to assume that it's a bad link and that I should move on to my next link in a set of "possible links."

How do I tell the WebClient to stop attempting to download after some predetermined amount of time?

I suppose I could use a thread, but if it's taking longer than one second to download, that's ok. I just want to make sure that it's connecting with the site.

Perhaps I should modify the WebClient headers, but I don't see what I should modify.

Perhaps I should use some other class in the System.Net namespace?

Answer 1

If you use the System.Net.WebRequest class you can set theTimeout property to be short and handle timeout exceptions.

try{
    var request = WebRequest.Create("http://www.contoso.com");
    request.Timeout = 5000; //set the timeout to 5 seconds
    request.Method = "GET";
    var response = request.GetResponse();
}
catch(WebException webEx){
   //there was an error, likely a timeout, try another link here
}