我正在尝试使用HttpWebRequest验证Url的存在。我发现了一些基本上可以做到这一点的例子:
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(Url);
request.Method = "HEAD";
using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
{
return response.StatusCode;
}
但是,如果url确实损坏了,则不会返回响应,而是引发异常。
我将代码修改为:
try
{
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(Url);
request.Method = "HEAD";
using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
{
return response.StatusCode;
}
}
catch (System.Net.WebException ex)
{
var response = ex.Response as HttpWebResponse;
return response == null ? HttpStatusCode.InternalServerError : response.StatusCode;
}
这似乎终于完成了我想要的。
但是我想知道,为什么请求抛出异常而不是返回带有NotFound状态码的响应?
最佳答案
是的,当网页大量使用状态代码并且并非全部都是错误时,这可能会很烦人。这会使 body 加工变得很痛苦。我个人使用此扩展方法来获取响应。
public static class HttpWebResponseExt
{
public static HttpWebResponse GetResponseNoException(this HttpWebRequest req)
{
try
{
return (HttpWebResponse)req.GetResponse();
}
catch (WebException we)
{
var resp = we.Response as HttpWebResponse;
if (resp == null)
throw;
return resp;
}
}
}