How do I add these variables within event blocks (EXTENSIONS ONLY)

[AyProductions]

How do I add a variable to my block in an extension for this. What code i need?

[gordonlu310]

Do you mean a parameter?

From App Inventor Sources here -

  @SimpleEvent (description = "Event indicating that the contents of the file have been written.")
  public void AfterFileSaved(String fileName) {
    // invoke the application's "AfterFileSaved" event handler.
    EventDispatcher.dispatchEvent(this, "AfterFileSaved", fileName);
  }

[AyProductions]

yes I meant that

thanks for it!