How to verify whether a URL exists in C#
Your code uses the WebClient class to retrieve data from the URL. However, when the user enters a stock symbol that does not exist, a runtime error is encountered. In order to solve this problem, you need a way to check if the URL is valid before trying to download it.
How to use HTTPWebRequest:
One way is to use the HttpWebRequest class. Here is an example implementation:
private bool RemoteFileExists(string url)
{
try
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "HEAD";
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
return (response.StatusCode == HttpStatusCode.OK);
}
}
catch
{
return false;
}
}
This method sends an HTTP HEAD request to the URL. If the response code is 200 (OK), it means the file exists and is accessible. Otherwise, it returns false.
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