Is there an elegant way to make every method in a class start with a certain block of code in C#?

Question

I have a class where every method starts the same way:

internal class Foo {
  public void Bar() {
    if (!FooIsEnabled) return;
    //...
  }
  public void Baz() {
    if (!FooIsEnabled) return;
    //...
  }
  public void Bat() {
    if (!FooIsEnabled) return;
    //...
  }
}

Is there a nice way to require (and hopefully not write each time) the FooIsEnabled part for every public method in the class?

I check Is there an elegant way to make every method in a class start with a certain block of code?, but that question is for Java, and its answer are using Java Library.

Answer 1

The principal your are looking for is Interception from the domain of Aspect Oriented Programming or AOP.

While C# does not directly support it, there are solid choices:

1. Postsharp
2. Unity Interception
3. Spring.NET
4. Castle Interceptors

If I get time tomorrow, I will cook up an example for you...

Answer 2

I don't think you can easily get rid of the extra clutter in the Bar, Baz, Bat methods, but you can make it more manageable with creating a method to execute action you are passing in as such.

internal class Foo
{
    private bool FooIsEnabled;

    public void Bar()
    {
        Execute(() => Debug.WriteLine("Bar"));
    }

    public void Baz()
    {
        Execute(() => Debug.WriteLine("Baz"));
    }

    public void Bat()
    {
        Execute(() => Debug.WriteLine("Bat"));
    }

    public void Execute(Action operation)
    {
        if (operation == null)
            throw new ArgumentNullException("operation");

        if (!FooIsEnabled)
            return;

        operation.Invoke();
    }
}