Should You Use Empty Delegates for Events or Opt for an Extension Method Approach?

Addressing the Drawbacks of Adding Anonymous Empty Delegates to Event Declarations

While the practice of adding anonymous empty delegates on event declarations offers the benefit of avoiding null checks, concerns arise regarding its potential downsides.

Performance Considerations

Contrary to concerns, using an empty event subscriber does not introduce a noticeable performance hit. The overhead associated with calling an empty delegate is minimal and unlikely to impact application performance significantly.

Maintenance Headaches

The use of empty event subscribers is relatively uncommon, which means it may not be immediately evident to future maintainers. However, using descriptive naming conventions and code documentation can help mitigate this potential issue.

Alternative Approach: Null-Check Mitigation using Extension Method

Instead of relying on empty event subscribers, an alternative approach is to use an extension method that encapsulates the null check. This approach provides the following advantages:

• Clarity and Conciseness: The extension method provides a single, consistent way to handle null events.
• Code Reusability: The method can be used throughout the application, reducing repetitive null checks.
• Improved Readability: By eliminating null checks from event invocations, the code becomes more streamlined and easier to understand.

Example

The following extension method can be defined to handle null event checks:

public static void Raise(this EventHandler handler, object sender, EventArgs e)
{
    if (handler != null)
    {
        handler(sender, e);
    }
}

Using this extension method, event invocations can be simplified, even for null events:

// Works, even for null events.
MyButtonClick.Raise(this, EventArgs.Empty);

By using the extension method approach, the concerns associated with empty event subscribers can be addressed while maintaining the benefits of streamlined event handling.

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