WebClient downloads file that "sounds similar"

Question

I'm in a situation where I know the systematics of filenames on a server, but not how many there are. Like abc_1.jpg, abc_2.jpg and so on. My idea was to just try downloading until a file does not exist – > if abc_1 exists, also try downloading 2 and so on. What actually happens is that instead of stopping the download as soon as a file does not exist it will keep downloading a file that sounds similar, in my case it will keep downloading abc_1.jpg when being asked for 2, 3, and so on. Any way to avoid that?

Here is the code

 if (client == null)
    {
        client = new WebClient();
        client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(client_DownloadProgressChanged);
        client.DownloadFileCompleted += new System.ComponentModel.AsyncCompletedEventHandler(DownloadFileCompleted);
    }
     
     uri = "http://" + serverAdress + downloadTasks[0];
    client.DownloadFileAsync(new System.Uri(uri, UriKind.Absolute), Application.persistentDataPath + "/" + newFileName);
downloadTasks.RemoveAt(0);

Answer 1

Well then, answering my own question. Was looking at the wrong end of the problem. It's not WebClient, it's the Apache Server:

"If the server receives a request for /some/dir/foo and /some/dir/foo does not exist, then the server reads the directory looking for all files named foo.*, and effectively fakes up a type map which names all those files, assigning them the same media types and content-encodings it would have if the client had asked for one of them by name. It then chooses the best match to the client's requirements, and returns that document."