In C#, get the file name from the URI string.

Problem

This is the approach I use to get the file name from a string URI. What can I do to improve its sturdiness?

private string GetFileName(string hrefLink)
{
    string[] parts = hrefLink.Split('/');
    string fileName = "";

    if (parts.Length > 0)
        fileName = parts[parts.Length - 1];
    else
        fileName = hrefLink;

    return fileName;
}

Asked by paulwhit

Solution #1

Simply create a System.Uri object, check if it’s a file with IsFile, and then use Uri.LocalPath to extract the filename.

This is significantly safer because it also allows you to verify the URI’s validity.

In response to a comment, I’ve made the following changes:

I’d use the following command to acquire the whole filename:

Uri uri = new Uri(hreflink);
if (uri.IsFile) {
    string filename = System.IO.Path.GetFileName(uri.LocalPath);
}

This handles all error checking for you and is platform-independent. All of the unique situations are handled quickly and efficiently for you.

Answered by Reed Copsey

Solution #2

Uri. http urls aren’t supported by IsFile. Only “file:/” is supported. “The IsFile property is true when the Scheme property equals UriSchemeFile,” according to MSDN. As a result, you can’t rely on it.

Uri uri = new Uri(hreflink);
string filename = System.IO.Path.GetFileName(uri.LocalPath);

Answered by Le Zhang

Solution #3

The majority of other answers are either incomplete or ignore anything after the path (query string/hash).

readonly static Uri SomeBaseUri = new Uri("http://canbeanything");

static string GetFileNameFromUrl(string url)
{
    Uri uri;
    if (!Uri.TryCreate(url, UriKind.Absolute, out uri))
        uri = new Uri(SomeBaseUri, url);

    return Path.GetFileName(uri.LocalPath);
}

Test results:

GetFileNameFromUrl("");                                         // ""
GetFileNameFromUrl("test");                                     // "test"
GetFileNameFromUrl("test.xml");                                 // "test.xml"
GetFileNameFromUrl("/test.xml");                                // "test.xml"
GetFileNameFromUrl("/test.xml?q=1");                            // "test.xml"
GetFileNameFromUrl("/test.xml?q=1&x=3");                        // "test.xml"
GetFileNameFromUrl("test.xml?q=1&x=3");                         // "test.xml"
GetFileNameFromUrl("http://www.a.com/test.xml?q=1&x=3");        // "test.xml"
GetFileNameFromUrl("http://www.a.com/test.xml?q=1&x=3#aidjsf"); // "test.xml"
GetFileNameFromUrl("http://www.a.com/a/b/c/d");                 // "d"
GetFileNameFromUrl("http://www.a.com/a/b/c/d/e/");              // ""

Answered by Ronnie Overby

Solution #4

For http urls, the accepted answer is problematic. In addition, Uri. LocalPath performs Windows-specific conversions and, as one user pointed out, includes query strings. Uri is a better option. AbsolutePath

For http urls, the proper procedure is as follows:

Uri uri = new Uri(hreflink);
string filename = System.IO.Path.GetFileName(uri.AbsolutePath);

Answered by Kostub Deshmukh

Solution #5

This, I believe, will suffice:

var uri = new Uri(hreflink);
var filename = uri.Segments.Last();

Answered by Zeus82

Post is based on https://stackoverflow.com/questions/1105593/get-file-name-from-uri-string-in-c-sharp