Wake on lan demo added

DemoAndroid/Activities/WakeOnLanActivity.cs

@@ -0,0 +1,53 @@
+using System.Net;
+using System.Net.Sockets;
+
+namespace DemoAndroid;
+
+[Activity(Label = "WakeOnLanActivity")]
+public class WakeOnLanActivity : Activity
+{
+    protected override void OnCreate(Bundle? savedInstanceState)
+    {
+        base.OnCreate(savedInstanceState);
+
+        // Create your application here
+        SetContentView(Resource.Layout.activity_wakeonlan);
+
+        var button = FindViewById<Button>(Resource.Id.btnWakeOnLan);
+        button.Click += (sender, args) =>
+        {
+            WakePc();
+        };
+    }
+
+    private void WakePc()
+    {
+        byte[] macAddress = { 0x2c, 0x4d, 0x54, 0x4d, 0x10, 0x0f };
+        byte[] magicPacket = new byte[102];
+
+        // Fill first 6 bytes with 0xFF
+        for (int i = 0; i < 6; i++)
+        {
+            magicPacket[i] = 0xFF;
+        }
+
+        // Repeat MAC address 16 times
+        for (int i = 1; i <= 16; i++)
+        {
+            for (int j = 0; j < 6; j++)
+            {
+                magicPacket[i * 6 + j] = macAddress[j];
+            }
+        }
+
+        using var client = new UdpClient();
+        client.EnableBroadcast = true;
+        var endpoint = new IPEndPoint(IPAddress.Broadcast, 9); // 255.255.255.255 port 9
+
+        for (int i = 0; i < 5; i++)
+        {
+            // Try 5 times
+            client.Send(magicPacket, magicPacket.Length, endpoint);
+        }
+    }
+}