I posted the following message on a developer list. I’m so frustrated by the lack of alternatives to nCover…..

We’ve been using the free version of NCover in a number of our projects (v1.5.8), and for the most part, we’re happy with what it does.

However we’ve recently come to realise that the free download for nCover doesn’t work on x64 machines (incompatibility when it tries to register the profiling DLL). This prompted me to have a look for another free/OSS product which would work in the same or similar manner as nCover….and i’m coming back empty-handed.

Am i the only person who has questioned why i should need to purchase the enterprise version of the product, just for x64 support? And more importantly, how come there is a complete drought of alternatives for nCover? I’ve found PartCover, but haven’t used it and it doesn’t look to be as complete as nCover….

I’m shocked, given that the OSS community seems mad about creating alternatives and derivatives for toolsets (think NUnit vs MBUNit vs xUnit or NMock vs Rhino Mocks vs Moq …). There seems to be a number of alternatives for other TDD tools, but as far as coverage goes, is nCover really the only thing out there?

If you know any, i’d like to hear about it….

I’ve recently been getting my hands dirty with WPF as a successor to WinForms, and one thing is for sure – its like i’m starting from ground zero, all over again…

What I’ve recently wanted to do was to learn the details of animation in WPF. I’ve read a lot about the animation frameworks built into WPF, and the fact that they can be programmed directly into the XAML is quite interesting. Seems that it XAML is a whole lot more than a mark-up language. It’s so expressive it is almost like code.


<window x:Class="WPFAnimatingPath.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1" Height="300" Width="300">
</window><window .Resources>
<storyboard x:Key="pointAnimation">
<pointanimation From="55, 10" To="55, 150" RepeatBehavior="Forever" AutoReverse="True" Storyboard.TargetName="seg1" Storyboard.TargetProperty="Point1" AccelerationRatio="0.5" DecelerationRatio="0.5" Duration="0:00:10" />
<pointanimation From="105, 150" To="105, 10" RepeatBehavior="Forever" AutoReverse="True" Storyboard.TargetName="seg2" Storyboard.TargetProperty="Point1" AccelerationRatio="0.5" DecelerationRatio="0.5" Duration="0:00:05" />
</storyboard>
</window>
<grid>
<button Name="btnAnimate" Margin="0,37,0,0" Click="btnAnimate_Click">
<stackpanel Height="200" Width="160">
<textblock TextAlignment="Center" Height="40" VerticalAlignment="Bottom" FontSize="16">Click me</textblock>
<path Stroke="BlueViolet" StrokeThickness="2" Width="160" Height="160">
</path><path .Triggers>
<eventtrigger RoutedEvent="Path.Loaded">
<beginstoryboard>
<storyboard>
<doubleanimation Storyboard.TargetName="rotation" Storyboard.TargetProperty="Angle" From="-30" To="30" Duration="0:0:05" RepeatBehavior="Forever" AutoReverse="True" AccelerationRatio="0.5" DecelerationRatio="0.5" />
</storyboard>
</beginstoryboard>
</eventtrigger>
</path>
<path .RenderTransform>
<rotatetransform x:Name="rotation" CenterX="80" CenterY="80" Angle="0" />
</path>
<path .Data>
<pathgeometry>
</pathgeometry><pathgeometry .Figures>
<pathfigure StartPoint="0, 80">
<linesegment Point="30, 80" />
<quadraticbeziersegment x:Name="seg1" Point1="55, 10" Point2="80, 80" />
<quadraticbeziersegment x:Name="seg2" Point1="105, 150" Point2="130, 80" />
<linesegment Point="160, 80" />
</pathfigure>
</pathgeometry>

</path>

</stackpanel>
</button>
</grid>

What i’ve written here is a simple application which displays a button on the page. Like my last post about XAML and the mindset change, this code allows me to embed whatever i want into the content of the Button, and in this case, i have 2 bezier arcs which form a pseudo SINE wave. when you click the button, the arcs animate and flow in a throbbing fashion.

These are the basics which demonstrate:

  • Window Resources
  • Embedded Content
  • Drawing arcs/lines
  • Animating objects

Covariance and Contravariance are terms used in programming languages and set theory to define the behaviour of parameter and return types of a function.

Yes, that’s a mouthful, but in a nutshell:

  • Covariance mandates that the return type and the parameters of a function must be a subtype of the original base class type for any superclass
  • Contravariance allows the return type and/or the parameter types to be super-types of the defined types and not necessarily sub-types

Nothing better than using an example:

[HTML1]

In this example:

  • Animal is a superclass.
  • Human is a subclass of Animal, with a covariant (no change) override to the CreateChild method to return the looser type Animal
  • Dog is a subclass of Animal, with a contravariant override to the CreateChild method to return the stronger type Dog

More reading on Eric Lippert’s blog series on Covariance and Contravariance in C#

EDIT: I thought it best prudent that I clarify that this is only one example of where variance is used. Method signatures, delegates and arrays are some more examples of where the theory of co and contra variance can be found.

short post…..

In some cases, the .NET framework will throw an exception internally, and then (using it’s own exception handling routines) re-throw something else based on that exception. if you’re getting an exception thrown from the Framework which you don’t really understand, and can’t work out what is causing the problem, try turning on the First Chance Exception for the .NET CLR in VS (Debug –> Exceptions).

This allows VS to catch any CLR exceptions when they are thrown, and will give you more insight into what’s the root cause of the problem.

Also, make sure you turn it off when you’re done otherwise you could end up constantly chasing your tail catching unnecessary exceptions 😉