Path.Combine for URLs?

Question

Path.Combine is handy, but is there a similar function in the .NET framework for URLs?

I'm looking for syntax like this:

Url.Combine("http://MyUrl.com/", "/Images/Image.jpg")

which would return:

"http://MyUrl.com/Images/Image.jpg"

Answer 1

Use:

    private Uri UriCombine(string path1, string path2, string path3 = "", string path4 = "")
    {
        string path = System.IO.Path.Combine(path1, path2.TrimStart('\\', '/'), path3.TrimStart('\\', '/'), path4.TrimStart('\\', '/'));
        string url = path.Replace('\\','/');
        return new Uri(url);
    }

It has the benefit of behaving exactly like Path.Combine.

Answer 2

Use this:

public static class WebPath
{
    public static string Combine(params string[] args)
    {
        var prefixAdjusted = args.Select(x => x.StartsWith("/") && !x.StartsWith("http") ? x.Substring(1) : x);
        return string.Join("/", prefixAdjusted);
    }
}

Answer 3

I find the following useful and has the following features :

• Throws on null or white space
• Takes multiple params parameter for multiple Url segments
• throws on null or empty

Class

public static class UrlPath
{
   private static string InternalCombine(string source, string dest)
   {
      if (string.IsNullOrWhiteSpace(source))
         throw new ArgumentException("Cannot be null or white space", nameof(source));

      if (string.IsNullOrWhiteSpace(dest))
         throw new ArgumentException("Cannot be null or white space", nameof(dest));

      return $"{source.TrimEnd('/', '\\')}/{dest.TrimStart('/', '\\')}";
   }

   public static string Combine(string source, params string[] args) 
       => args.Aggregate(source, InternalCombine);
}

Tests

UrlPath.Combine("test1", "test2");
UrlPath.Combine("test1//", "test2");
UrlPath.Combine("test1", "/test2");

// Result = test1/test2

UrlPath.Combine(@"test1\/\/\/", @"\/\/\\\\\//test2", @"\/\/\\\\\//test3\") ;

// Result = test1/test2/test3

UrlPath.Combine("/test1/", "/test2/", null);
UrlPath.Combine("", "/test2/");
UrlPath.Combine("/test1/", null);

// Throws an ArgumentException

Answer 4

I found UriBuilder worked really well for this sort of thing:

UriBuilder urlb = new UriBuilder("http", _serverAddress, _webPort, _filePath);
Uri url = urlb.Uri;
return url.AbsoluteUri;

See UriBuilder Class - MSDN for more constructors and documentation.

Answer 5

I have combined all the previous answers:

    public static string UrlPathCombine(string path1, string path2)
    {
        path1 = path1.TrimEnd('/') + "/";
        path2 = path2.TrimStart('/');

        return Path.Combine(path1, path2)
            .Replace(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar);
    }

    [TestMethod]
    public void TestUrl()
    {
        const string P1 = "http://msdn.microsoft.com/slash/library//";
        Assert.AreEqual("http://msdn.microsoft.com/slash/library/site.aspx", UrlPathCombine(P1, "//site.aspx"));

        var path = UrlPathCombine("Http://MyUrl.com/", "Images/Image.jpg");

        Assert.AreEqual(
            "Http://MyUrl.com/Images/Image.jpg",
            path);
    }

Answer 6

My generic solution:

public static string Combine(params string[] uriParts)
{
    string uri = string.Empty;
    if (uriParts != null && uriParts.Any())
    {
        char[] trims = new char[] { '\\', '/' };
        uri = (uriParts[0] ?? string.Empty).TrimEnd(trims);

        for (int i = 1; i < uriParts.Length; i++)
        {
            uri = string.Format("{0}/{1}", uri.TrimEnd(trims), (uriParts[i] ?? string.Empty).TrimStart(trims));
        }
    }

    return uri;
}