Getting the parent name of a URI/URL from absolute name C#

Question

Hello,

Given an absolute URI/URL, I want to get a URI/URL which doesn't contain the leaf portion. For example: given http://foo.com/bar/baz.html, I should get http://foo.com/bar/.

The code which I could come up with seems a bit lengthy, so I'm wondering if there is a better way.

static string GetParentUriString(Uri uri)
    {            
        StringBuilder parentName = new StringBuilder();

        // Append the scheme: http, ftp etc.
        parentName.Append(uri.Scheme);            

        // Appned the '://' after the http, ftp etc.
        parentName.Append("://");

        // Append the host name www.foo.com
        parentName.Append(uri.Host);

        // Append each segment except the last one. The last one is the
        // leaf and we will ignore it.
        for (int i = 0; i < uri.Segments.Length - 1; i++)
        {
            parentName.Append(uri.Segments[i]);
        }
        return parentName.ToString();
    }

One would use the function something like this:

  static void Main(string[] args)
    {            
        Uri uri = new Uri("http://foo.com/bar/baz.html");
        // Should return http://foo.com/bar/
        string parentName = GetParentUriString(uri);                        
    }

Thanks, Rohit

Answer 1

This is the shortest I can come up with:

static string GetParentUriString(Uri uri)
{
    return uri.AbsoluteUri.Remove(uri.AbsoluteUri.Length - uri.Segments.Last().Length);
}

If you want to use the Last() method, you will have to include System.Linq.

Answer 2

Quick and dirty

int pos = uriString.LastIndexOf('/');
if (pos > 0) { uriString = uriString.Substring(0, pos); }

Answer 3

There must be an easier way to do this with the built in uri methods but here is my twist on @unknown (yahoo)'s suggestion. In this version you don't need System.Linq and it also handles URIs with query strings.

    private static string GetParentUriString(Uri uri)
    {
        return uri.AbsoluteUri.Remove(uri.AbsoluteUri.Length - uri.Segments[uri.Segments.Length -1].Length - uri.Query.Length);
    }

Answer 4

Shortest way I found:

static Uri GetParent(Uri uri) {
    return new Uri(uri, Path.GetDirectoryName(uri.LocalPath) + "/");
}