CODEWITHSUNDEEP
c#xmlregexsilverlight
Dan Sewell
Dan Sewell

Reputation: 1290

c# Regex on XML string handler

Trying to fiddle around with regex here, my first attempt. Im trying to extract some figures out of content from an XML tag. The content looks like this:

www.blahblah.se/maps.aspx?isAlert=true&lat=51.958855252721&lon=-0.517657021473527

I need to extract the lat and long numerical vales out of each link. They will always be the same amount of characters, and the lon may or may not have a "-" sign.

I thought about doing it like this below (its obviously not right though): (The string in question is in the "link" tag):

             var document = XDocument.Load(e.Result);
             if (document.Root == null)
             return;

            var events = from ev in document.Descendants("item1")
                     select new
                     {
                         Title = (ev.Element("title").Value),
                         Latitude = Regex.xxxxxxx(ev.Element("link").Value, @"lat=(?<Lat>[+-]?\d*\.\d*)", String.Empty),
                         Longitude = Convert.ToDouble(ev.Element("link").Value),

                     };

        foreach (var ev in events)
        {
 do stuff
  }

Many thanks!

Upvotes: 1

Views: 550

Answers (2)

Brian Agnew
Brian Agnew

Reputation: 272367

If you have a URL with GET parameters, I would be tempted to find a library that can pull that apart for you, rather than using regexps. There may be edge cases that your regexp doesn't handle, but a library built for the specific purpose would handle (it depends on the set of data that you have to parse and how well-bounded it is, of course).

Upvotes: 0

Mark Byers
Mark Byers

Reputation: 838946

Try this:

Regex.Match(ev.Element("link").Value, @"lat=(?<Lat>[+-]?\d*\.\d*)").Groups[1].Value

Example:

string ev = "www.blahblah.se/maps.aspx?isAlert=true&lat=51.958855252721&lon=-0.517657021473527";
string s = Regex.Match(ev, @"lat=(?<Lat>[+-]?\d*\.\d*)").Groups[1].Value;

Result:

"51.958855252721"

Upvotes: 1

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