Projektdateien hinzufügen.

WindowsFormsApp1/OP/ISubject.cs

@@ -0,0 +1,23 @@
+namespace WindowsFormsApp1.OP
+{
+    public interface ISubject<T>
+    {
+        /// <summary>
+        /// Attach an observer to the object.
+        /// </summary>
+        /// <param name="observer">Your Observer.</param>
+        void Subscribe(IObserver<T> observer);
+        /// <summary>
+        /// Detach an observer from an object.
+        /// </summary>
+        /// <param name="observer">Your observer.</param>
+        void Unsubscribe(IObserver<T> observer);
+        /// <summary>
+        /// Notify all observers about an event.
+        /// </summary>
+        void Notify();
+
+        void SetState(T state);
+        T GetState();
+    }
+}