getting querystring from string

I was having a URL as string
e.g. string videoURL="http://www.youtube.com/watch?v=Rz-Lejndrys";

So now if I wanted to get the value of querstring v. We can get sub-string of videoURL or there is one more method to fetch value of v from above string.

 Uri videoPrevUri = new Uri(videoURL);
 string videoID = HttpUtility.ParseQueryString(videoPrevUri.Query).Get("v");

videoID will return you the value of v