Posts

I asked around while trying to learn how to use LINQ. LINQ is essentially SQL for .NET—it allows you to query objects directly in memory. For example: List<int> test = new List<int> { 1, 3, 5 }; List<int> testnew = (from a in test where a == 5 select a).ToList(); Someone claimed LINQ was faster than using foreach for selecting items. So, I tested it. The Benchmark static List<int> testlist = new List<int>(); static void Main(string[] args) { DateTime b, a; List<double> regularTimes = new List<double>(); List<double> LINQTimes = new List<double>(); for (int x = 0; x < 1000000; x++) testlist.Add(x * 5); // Foreach loop test for (int x = 0; x < 1000; x++) { b = DateTime.Now; TestRegular(); a = DateTime.Now; regularTimes.Add((a - b).TotalMilliseconds); } Console.WriteLine("Regular Avg.: {0}", regularTimes.Average()); // LINQ test for (int x = 0; x < 1000; x++) { b = DateTime.Now; TestLINQ(); a = DateTime.Now; LINQTimes.Add((a - b).TotalMilliseconds); } Console.WriteLine("LINQ Avg.: {0}", LINQTimes.Average()); Console.ReadLine(); } private static void TestRegular() { List<int> newlist = new List<int>(); foreach (int item in testlist) if (item % 2000 == 0) newlist.Add(item); } private static void TestLINQ() { var newlist = (from a in testlist where a % 2000 == 0 select a).ToList(); } This runs each selection method 1000 times on a list of 1,000,000 items. ...

An Introduction So, I’m moving into an apartment in the near future. Following that, I will have to learn how to manage my documents and ensure I can find them back in time. I’ve thought of a few solutions, one of them being what I do now – where I simply have a folder with PDFs of my documents (I digitalize everything). This works fine now… (I have like … 20 documents)… But it may not work in 2 years when I have a hundred documents spread over many different corporations and years. ...

I’ve long wanted to write a Bencoding library. Bencoding is an encoding format for encoding objects like text, lists, dictionaries, etc., into a single piece of text. It’s often used for transporting configuration files. Bencoding is most famous for its use in the Bittorrent protocol—it forms the basis for .torrent files. I wanted to create a C# library to support all known Bencoding object types. You can read more about the encoding here. ...

Introduction For my previous post, where I find the signal strength of WiFi spots, I also needed an algorithm to actually locate the spot. I decided to use triangulation, which is commonly used in wireless communications to locate devices based on signal strength from known positions. As my system uses GPS, I had to consider the Earth’s curvature. Calculating the geographic midpoint on a sphere isn’t trivial, but GeoMidpoint provides a great explanation (Method A). ...

Introduction I’ve long wanted to build a WiFi-based application—ideally one that also records GPS location data for wardriving. I searched for manageable C# solutions integrated with .NET. First Attempts I explored many WMI tutorials, but on Windows 7, I lacked the needed namespaces like MSNdis_80211_ServiceSetIdentifier. Eventually, I discovered the WLan API (available since Windows XP SP3), usable via P/Invoke. Fortunately, someone made a ManagedWifi wrapper for it—perfect! The Scanner I wrote a small utility that scans for SSIDs across all interfaces and retrieves their MAC addresses. ...