From 95b5f9a4c4fa17b1d4854185a08e2a3434944de0 Mon Sep 17 00:00:00 2001
From: ksami <ksami.ihide@gmail.com>
Date: Tue, 24 Oct 2017 13:29:11 +0800
Subject: #2314 add delegates and events to csharp/en

---
 csharp.html.markdown | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

(limited to 'csharp.html.markdown')

diff --git a/csharp.html.markdown b/csharp.html.markdown
index c98a7da9..24ce803e 100644
--- a/csharp.html.markdown
+++ b/csharp.html.markdown
@@ -640,6 +640,54 @@ on a new line! ""Wow!"", the masses cried";
         }
     }
 
+
+    // DELEGATES AND EVENTS
+    public class DelegateTest
+    {
+        public static int count = 0;
+        public static int Increment()
+        {
+            // increment count then return it
+            return ++count;
+        }
+
+        // A delegate is a reference to a method
+        // To reference the Increment method,
+        // first declare a delegate with the same signature
+        // ie. takes no arguments and returns an int
+        public delegate int IncrementDelegate();
+
+        // An event can also be used to trigger delegates
+        // Create an event with the delegate type
+        public static event IncrementDelegate MyEvent;
+
+        static void Main(string[] args)
+        {
+            // Refer to the Increment method by instantiating the delegate
+            // and passing the method itself in as an argument
+            IncrementDelegate inc = new IncrementDelegate(Increment);
+            Console.WriteLine(inc());  // => 1
+
+            // Delegates can be composed with the + operator
+            IncrementDelegate composedInc = inc;
+            composedInc += inc;
+            composedInc += inc;
+
+            // composedInc will run Increment 3 times
+            Console.WriteLine(composedInc());  // => 4
+
+
+            // Subscribe to the event with the delegate
+            MyEvent += new IncrementDelegate(Increment);
+            MyEvent += new IncrementDelegate(Increment);
+
+            // Trigger the event
+            // ie. run all delegates subscribed to this event
+            Console.WriteLine(MyEvent());  // => 6
+        }
+    }
+
+
     // Class Declaration Syntax:
     // <public/private/protected/internal> class <class name>{
     //    //data fields, constructors, functions all inside.
-- 
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