Extension methods are gonna be fun!

casper — Wed, 23 May 2007 13:46:00 GMT

So I've had a (very) small amount of time to play around with Orcas and Silverlight, but some of the C# 3.0 features are going to come in handy. Greg Schechter has already written about using object initializers with XAML objects and back in March Scott Guthrie showed an example of extension methods. I've already come up with a nice little use for the latter.

Because of its declarative nature, there are some properties you can set quite easily inside XAML, but not so easily in C# — specifying the Canvas position for an object is one of those.

<Rectangle Canvas.Left="100" Canvas.Top="50" Width="10" Height="10/>

Rectangle r = new Rectangle();
r.SetProperty<double>(Canvas.Left, 100);
r.SetProperty<double>(Canvas.Top, 50);

Here's a nice little way object extensions can simplify your life.

public static class SilverlightExtensions
{
   public static void SetCanvasPosition(this Visual v, double left, double top)
   {
      v.SetValue<double>(Canvas.LeftProperty, left);
      v.SetValue<double>(Canvas.TopProperty, top);
   }
}

Because I need to be able to create a ton of Rectangles programmatically, I can replace the two earlier lines of code with one

r.SetCanvasPosition(100, 50);

Happy New Year! Now back to work :)

casper — Thu, 04 Jan 2007 11:23:00 GMT

First off, let me wish everyone a Happy New Year and the best of luck with those millions of New Year's resolutions which seem to be flying around the place. I'm sure the cloud tag over at 43things is dominated by subjects related to weight loss/fitness/all that good stuff. My own commitment for work is to continue searching for better ways to do things: whether it's coding, planning, or our daily game of foosball. I'd like to make a commitment to blog twice a week, but unless I stumble across a fountain of ideas, that seems unlikely.

I'm currently working on a class that needs to store unique information, so naturally I've got a Dictionary tucked away with a couple of accessor methods. While writing my tests, I decided that returning 0 for non-existent values rather than throwing would be more appropriate. So, I punched in the following test and then made it pass.

[Test]
public void RetrievingANonExistentStatisticReturnsZero()
{
  Campaign c = new Campaign();

  double value = c.GetStatistic("non-existent");

  Assert.AreEqual(0, value);
}

The first implementation I wrote for GetStatistic() used Dictionary.ContainsKey() and then I immediately wondered if TryGetValue() would be any faster. After all, the MSDN docs say they both approach O(1).

Remembering my experience with enums, I whipped up another small benchmark. This time, though, there was only a minute difference, so I'm sticking with the ContainsKey version. It's tough being so curious at times ;)

Adventures of an aspiring agile developer in a not-quite agile world : C#

Extension methods are gonna be fun!

Happy New Year! Now back to work :)