Add project files.

src/apps/Elsa.Server.Web/Activities/CustomEvent.cs

@@ -0,0 +1,18 @@
+using Elsa.Expressions.Models;
+using Elsa.Workflows;
+using Elsa.Workflows.Runtime.Activities;
+
+namespace Elsa.Server.Web.Activities;
+
+public class CustomEvent : EventBase<object>
+{
+    protected override string GetEventName(ExpressionExecutionContext context)
+    {
+        return "MyEvent";
+    }
+    
+    protected override void OnEventReceived(ActivityExecutionContext context, object? eventData)
+    {
+        Console.WriteLine("Event received with data: " + eventData);
+    }
+}