WpfWithBddSpecFlowTest.cs

[Binding]
class CalculatorSteps
{
  private readonly StandardKernel _kernel = new StandardKernel();

  private ICalculator _calc;
  private int _lastResult;

  public CalculatorSteps()
  {
    _kernel.Bind<ICalculator>().To<Calculator>();
  }

  [Given(@"a calculator")]
  public void GivenACalculator()
  {
    _calc = _kernel.Get<ICalculator>();
  }

  [When(@"I sum (\d+) and (\d+)")]
  public void WhenISum(int num1, int num2)
  {
    _lastResult = _calc.Sum(num1, num2);
  }

  [Then(@"the result should be (\d+)")]
  public void ThenTheResultShouldBe(int result)
  {
    Assert.AreEqual(result, _lastResult);
  }
}