Question

i faced an issue with downloading file from website.

A user can fill in the textbox (example: hello.html) and then click on a button to download the html file. Now my issue is: even the file “hello.html” is not exists, my code will tend to download it as well. There will be “index.html” file appears in folder. How do I write “if” statement so that I can tell the code not to download if the file is not exist?

My code:

if (FILE NOT EXIST ON THE WEBSITE)
         {
              //MessageBox.Show("There is no such file on the website. Please check your spelling.");             
         }
         else
         {
              client.DownloadFile("http://example.com/" + txtbox.Text.ToUpper().ToString(),
                                                sourceDir + txtbox.Text.ToUpper().ToString() + ".html");
         }

Thank you so much.

Answer 1

System.IO.File.Exists(fpath) returns false in Chrome and Firefox

if (File.Exists(fileLocation))
{ 
    // Download File!
}

That problem is specific for uploading but its the same concept.

OR:

Taken Directly from: http://www.dotnetthoughts.net/how-to-check-remote-file-exists-using-c/

Add this method to your class.

private bool RemoteFileExists(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 = "HEAD";
        //Getting the Web Response.
        HttpWebResponse response = request.GetResponse() as HttpWebResponse;
        //Returns TURE if the Status code == 200
        return (response.StatusCode == HttpStatusCode.OK);
    }
    catch
    {
        //Any exception will returns false.
        return false;
    }
}

Then when you want to check if a file exists at a url use this:

if (RemoteFileExists("http://blog.stackoverflow.com/wp-content/uploads/stackoverflow-logo-300.png")
{
    //File Exists
}
else
{
    //File does not Exist
}