Why is this simple cast not working?

[TheLurkingDev]

EventManager class:

public class EventManager : MonoBehaviour
   {
       public event EventHandler DialogEvent;

       public static void ProcessEvent(IEvent eventObject)
       {          
           EventManager eventMgr = ManagerRepo.Instance.EventMgr;
           switch (eventObject.Type)
           {
               case EventType.Unknown:
                   break;
               case EventType.Dialog:
                   eventMgr.DialogEvent(eventObject, EventArgs.Empty);
                   break;
               default:
                   break;
           }
       }
   }

And the handling method in another class:

private void HandleDialogEvent(object sender, EventArgs e)
       {
           NpcResponse response = sender as NpcResponse;
           Debug.Log("Event received for keyword: " + response.Keyword);
       }

The cast within the HandleDialogEvent method is not working and the variable response ends up being null.

Please check the attached screenshot for more details.

[Kiwasi]

As will return null if the object can’t be cast to the appropriate type. So always use a null check when using As.

If you know the type in advance, it’s better to use explicit casting. Or even better, properly type the argument coming in.