[英]Using HttpWebRequest and HttpWebResponse throws an error, however only on certain websites
此函數檢查url
是否為有效地址,並與http://www.google.com一起使用
public static bool CheckValidURL(string url)
{
try
{
//Creating the HttpWebRequest
HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
//Setting the Request method HEAD, you can also use GET too.
request.Method = "GET";
//Getting the Web Response.
HttpWebResponse response = request.GetResponse() as HttpWebResponse;
//Returns TRUE if the Status code == 200
bool isValid;
if (response.StatusCode == HttpStatusCode.OK)
{
isValid = true;
}
else
{
isValid = false;
}
response.Close();
return isValid;
}
catch
{
//Any exception will returns false.
return false;
}
}
單擊菜單項時將調用此代碼,用於更新卡的價格。 它在foreach
循環中,其中變量c
是自定義類MagicCard
。
string url = "";
string webCardName = c.name.ToLower().Replace(" ", "-").Replace(",", "").Replace("\'", "");
string webSetName = MagicCard.GetSetName(c).ToLower().Replace(" ", "-").Replace(",", "").Replace("\'", "");
url = string.Format("shop.tcgplayer.com/magic/{0}/{1}", webSetName, webCardName);
if (WebScraper.CheckValidURL(url) == false)
{
MessageBox.Show("ERROR: URL = " + url);
return;
}
最終URL的示例是此地址,盡管這是一個有效地址,但它被檢測為無效,並且任何其他卡都會產生類似的URL,這些URL也不起作用。 為什么會這樣呢?
您的站點需要一個User-Agent
。 我添加了這一行
request.UserAgent = "SO/1.0";
到您的代碼,並且有效。
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