System.Uri Class properties and parse URL names

System.Uri class provides an object representation of a uniform resource identifier (URI) and provides easy access to the parts of the URI. A URI is actually represents any resource available in an intranet or internet environment. URI points to the location of the resource.

By using the properties of the URI class, it is very easy to parse the URI into its sub-components.

You can easily create an instance of the System.Uri by the following line of code

Dim uri As New System.Uri("/articles/article.aspx?articleid=27")

One way of creating a URI object is using the Request object of the System.Web.HttpRequest namepace using the below code

Dim uri As System.Uri = Request.Url
or
Dim uri As System.Uri = Request.UrlReferrer

And now we can parse the URI into its components by using the class properties.

Property	Value for sample
AbsolutePath	/articles/article.aspx
AbsoluteUri	/articles/article.aspx?articleid=27
Authority	www.kodyaz.com
Host	www.kodyaz.com
LocalPath	/articles/article.aspx
OriginalString	/articles/article.aspx?articleid=27
PathAndQuery	/articles/article.aspx?articleid=27
Port	80
Query	?articleid=27
IsFile	False
Scheme	http
SchemeDelimiter	://

Let's make an other sample for  file shared over network.

Dim uri As New System.Uri("\\istw1947\share\cdonts.dll")

Property	Value for sample
AbsolutePath	/share/cdonts.dll
AbsoluteUri	file://istw1947/share/cdonts.dll
Authority	istw1947
Host	istw1947
LocalPath	\\istw1947\share\cdonts.dll
OriginalString	\\istw1947\share\cdonts.dll
PathAndQuery	/share/cdonts.dll
Port	-1
Query
IsFile	True
Scheme	file
SchemeDelimiter	://

I guess the above samples are at least a little bit self explaining.

OriginalString is the value passed to the constructor of the URI.

Authority is the Domain Name System (DNS) host name or the IP address of the URI resource which is the server name of the shared file or the domain name of the server hosting the resource.

You will notice that the IsFile boolean property as well as the Scheme differs between the two samples. For the web page the Scheme is http and the IsFile property is False. For the shared file the Scheme is file and the IsFile property is True.

Query property of the URI returns any query information included in the URI. For a web page as a URI, this points to the parameters passed to the page.

Port is the port number of this URI. For the web page sample the port property returns 80, but -1 for the shared folder sample.

There is many other properties of thte URI class that I have not listed here. One of them is IsLoopback property indicating whether the URI references the localhost.