[c#] Get host domain from URL?

how to get host domain from a string URL?

GetDomain has 1 input "URL", 1 Output "Domain"

Example1

INPUT: http://support.domain.com/default.aspx?id=12345
OUTPUT: support.domain.com

Example2

INPUT: http://www.domain.com/default.aspx?id=12345
OUTPUT: www.domain.com

Example3

INPUT: http://localhost/default.aspx?id=12345
OUTPUT: localhost

You should construct your string as URI object and Authority property returns what you need.

Try like this;

Uri.GetLeftPart( UriPartial.Authority )

Defines the parts of a URI for the Uri.GetLeftPart method.

http://www.contoso.com/index.htm?date=today --> http://www.contoso.com

http://www.contoso.com/index.htm#main --> http://www.contoso.com

nntp://news.contoso.com/[email protected] --> nntp://news.contoso.com

file://server/filename.ext --> file://server

Uri uriAddress = new Uri("http://www.contoso.com/index.htm#search");
Console.WriteLine("The path of this Uri is {0}", uriAddress.GetLeftPart(UriPartial.Authority));

Demo

 var url = Regex.Match(url, @"(http:|https:)\/\/(.*?)\/");

INPUT = "https://stackoverflow.com/questions/";

OUTPUT = "https://stackoverflow.com/";

Try this

Console.WriteLine(GetDomain.GetDomainFromUrl("http://support.domain.com/default.aspx?id=12345"));

It will output support.domain.com

Or try

Uri.GetLeftPart( UriPartial.Authority )

The best way, and the right way to do it is using Uri.Authority field

Load and use Uri like so :

Uri NewUri;

if (Uri.TryCreate([string with your Url], UriKind.Absolute, out NewUri))
{
     Console.Writeline(NewUri.Authority);
}

Input : http://support.domain.com/default.aspx?id=12345
Output : support.domain.com

Input : http://www.domain.com/default.aspx?id=12345
output : www.domain.com

Input : http://localhost/default.aspx?id=12345
Output : localhost

If you want to manipulate Url, using Uri object is the good way to do it. https://msdn.microsoft.com/en-us/library/system.uri(v=vs.110).aspx

WWW is an alias, so you don't need it if you want a domain. Here is my litllte function to get the real domain from a string

private string GetDomain(string url)
    {
        string[] split = url.Split('.');
        if (split.Length > 2)
            return split[split.Length - 2] + "." + split[split.Length - 1];
        else
            return url;

    }

try following statement

 Uri myuri = new Uri(System.Web.HttpContext.Current.Request.Url.AbsoluteUri);
 string pathQuery = myuri.PathAndQuery;
 string hostName = myuri.ToString().Replace(pathQuery , "");

Example1

 Input : http://localhost:4366/Default.aspx?id=notlogin
 Ouput : http://localhost:4366

Example2

 Input : http://support.domain.com/default.aspx?id=12345
 Output: support.domain.com

Use Uri class and use Host property

Uri url = new Uri(@"http://support.domain.com/default.aspx?id=12345");
Console.WriteLine(url.Host);