Hi there,
So...what I want to do, is to check if a certain URL is valid/exists, so I can download the file from that same URL.
If
the URL has a custom 404 page there's really no problem because if this
is the case, I'm able to download the file and then I can check if it's
the one I want. If the URL has not a custom page, however, then I'm
using WebRequest/WebResponse.
This is my code:
| //-> Check if url is valid |
| WebRequest serverRequest = WebRequest.Create(_url); |
| WebResponse serverResponse; |
| try //Try to get response from server |
| { |
| serverResponse = serverRequest.GetResponse(); |
| } |
| catch //If could not obtain any response |
| { |
| return 0; |
| } |
| |
| WebClient _client = new WebClient(); |
_client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(_client_DownloadProgressChanged);
|
| |
| _client.DownloadFileAsync(new Uri(_url), _destinationPath); //Download the file. |
So,
if the URL gets a valid response from 'serverResponse' then it
downloads the file, and I can later check if it's the one I want.
This all seems OK (I guess), and it works just fine......IF you only run this code once!
Let's
suppose the URL is valid. If I put the code above in a button click
event, for example, when I click the button the first time, it
downloads the file and everything is OK. However, if I click the button
a second time (after the first file has been successfully downloaded),
it just creates a file with 0 kb, overwriting the previous one, and
doesn't even go for the download.
I have no idea why this is
happening...the only thing I know, is that it is due to the
WebRequest/WebResponse part, because if I remove it, it goes just
fine...but then I can't check for a valid URL.
Is there any other way to check if the URL is valid? Or does anyone knows what's really happening?
I really appreciate any help here.
Carlos
p.s. sorry if this is not the right section...