如何使用ASP.Net/C#讀取客戶端URL的HTTP標頭狀態代碼

Question

在ASP.Net中使用C＃讀取URL時，需要讀取HTTP標頭的狀態（403或404）。 例如：URL1： https : //www.instagram.com/khaniki.ah URL2： https : //www.instagram.com/khaniki.ah123456當我嘗試讀取URL1時，狀態為200（HttpStatusCode.Found）用於讀取不存在的URL2； 在照片中查看更多。

另外，我使用以下代碼：

    var Url = UrlTbx.Text;
    Uri urlCheck = new Uri(Url);

    HttpWebRequest HttpRequest = (HttpWebRequest)WebRequest.Create(Url);
    HttpRequest.Timeout = 15000;
    HttpRequest.AllowAutoRedirect = false;
    HttpRequest.ServicePoint.Expect100Continue = false;
    HttpRequest.ContentType = "application/x-www-form-urlencoded";
    //HttpRequest.Method = "GET";
    HttpRequest.Method = "HEAD";//both methods was tested
    HttpWebResponse HttpResponse;

    try
    {
        HttpResponse = (HttpWebResponse)HttpRequest.GetResponse();

        if (HttpResponse.StatusCode == HttpStatusCode.Found)
            Lit.Text = "YES" + " / " + HttpResponse.StatusCode;
        else if (HttpResponse.StatusCode == HttpStatusCode.NotFound)
            Lit.Text = "NO" + " / " + HttpResponse.StatusCode;
    }
    catch (Exception)
    {
       return false;
    }

Answer 1

您請求的服務器似乎不接受HEAD請求。 嘗試保留GET標頭方法，然后嘗試刪除

HttpRequest.ContentType = "application/x-www-form-urlencoded";

還發現不是200。您在談論HttpStatusCode.OK為200。簡單地做時，我得到的是您要查找的404

   var Url = "https://www.instagram.com/khaniki.ah123456/";
   Uri urlCheck = new Uri(Url);

   HttpWebRequest HttpRequest = (HttpWebRequest)WebRequest.Create(Url);

   HttpRequest.Method = "Get";

   var dHttpWebResponse = await HttpRequest.GetResponseAsync();

或嘗試使用httpclient api（以避免異常）

var Url = "https://www.instagram.com/khaniki.ah123456/";
        Uri urlCheck = new Uri(Url);
        var client = new HttpClient();
        var res = client.GetAsync(urlCheck).Result;
        var statusCode = res.StatusCode; //should be 404