I haven't actually looked into LinqToXsd.
VB.NET GPX READER HOW TO
The guys extended the gpx standard by own namespaces and I simply don't know how to get those xsd's merged in a way, that I can access all data from within the classes generated by LinqToXsd. However, I for instance, am looking for a way of accessing geocaching gpx files downloadable from Groundspeak's website. Using it, it *should* be possible to get objectoriented access to the gpx files through linq like that:
If the "ele" element exists, the cast will return the "Value" property otherwise, it will return null.ĭid you already give Linq to XSD a try? You can find the toolset on codeplex. Waypoint.Element(gpx + "ele") != null ? waypoint.Element(gpx + "ele").Value : null The XElement class has an explicit cast to various types, which handles null elements. Deserializing the file into a model built from the schema would work too but I like the ability to dynamically filter it. My primary purpose in this post was to show how fast it is to use Linq to XML to get data out of a file and into an object model.
VB.NET GPX READER UPDATE
These objects are then sent to the data layer via WCF to update my database. Yes, if you notice the comments in the code, the spots where I append text to show the values that are pulled from the file are changed in my application to load my business objects. String.Format( "Name: " +Įh.wouldn't this be a good candidate for some Data Transfer Objects and Serialization? containers for the information retrieved. Waypoint.Element(gpx + "cmt").Value : null Waypoint.Element(gpx + "name").Value : null,ĭt = waypoint.Element(gpx + "cmt") != null ? Name = waypoint.Element(gpx + "name") != null ? Waypoint.Element(gpx + "ele").Value : null, Longitude = waypoint.Attribute( "lon").Value,Įlevation = waypoint.Element(gpx + "ele") != null ? Latitude = waypoint.Attribute( "lat").Value, Var waypoints = from waypoint in gpxDoc.Descendants(gpx + "wpt") Public string LoadGPXWaypoints( string sFile) / Normally, this would be used to populate the / string containing line delimited waypoints from / When passed a file, open it and parse all waypoints from it.
/ Load the namespace for a standard GPX document XDocument gpxDoc = XDocument.Load(sFile) Private XDocument GetGpxDoc( string sFile) Still it's crazy fast and I'm loading a lot of data in only a few lines of code. The biggest issue for me with Linq is the inability to debug line-by-line.
VB.NET GPX READER CODE
Also, when working with Xml, remember that an element that doesn't exist results in a null object reference so you'll see in the code how I handled that for each element. My initial run at this netted attribute values but no element values which was really frustrating. It's really pretty straight forward once you realize that you need to pull in the namespace object and then include it in each call to an element. The original file had about 6,500 lines in it. At the end of this post is a well formed (but incomplete) GPX file.
VB.NET GPX READER SOFTWARE
This gets it into the standardized format that nearly all other GPS units and mapping software can use and I'm ready to load my data. I load this file onto a machine with Garmin MapSource and immediately save the file as a GPX. My Garmin saves files in a GDB format which is proprietary for the product. When loaded, it will direct you to each point along the route in the appropriate order. It's essentially a list of positions you build by looking at a map or a file you get from someone else's track. RoutesĪ route is what you load into your GPS. When I get home I have a complete listing of a few hundred points on my route, depending on how far apart or how long to wait I've preset my GPS to mark between saved track points. GPS antennae have come a long way in the last few years and my inexpensive Garmin eTrex keeps pretty accurate markers even when I'm in a deep draw. When I want to mark out a trail for users of my application, I set up my GPS on my bike and just go for a ride. So when you get to the suspension bridge, mark a waypoint and you can find it again later as well as tell everyone else about it. In general, the major things that you will work with are: WaypointsĪ waypoint is a specific position that is manually marked by a user for future reference. A GPX file can contain a lot of different kinds of information. GPX is the standardized file format for GPS file exchanges.
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