Null checking

Author: blakepell

src/Avalon.Client/HashCommands/Beep.cs

@@ -43,19 +43,19 @@ public override void Execute()
                                    switch (o.BeepType)
                                    {
                                        case BeepType.Beep:
-                                           SystemSounds.Beep.Play();
+                                           SystemSounds.Beep?.Play();
                                            return;
                                        case BeepType.Asterisk:
-                                           SystemSounds.Asterisk.Play();
+                                           SystemSounds.Asterisk?.Play();
                                            return;
                                        case BeepType.Exclamation:
-                                           SystemSounds.Exclamation.Play();
+                                           SystemSounds.Exclamation?.Play();
                                            return;
                                        case BeepType.Hand:
-                                           SystemSounds.Hand.Play();
+                                           SystemSounds.Hand?.Play();
                                            return;
                                        case BeepType.Question:
-                                           SystemSounds.Question.Play();
+                                           SystemSounds.Question?.Play();
                                            return;
                                        case BeepType.Alert:
                                            // Special type, this will play even if other system sounds are muted.

src/Avalon.Client/HashCommands/ToastAlarm.cs

@@ -29,7 +29,7 @@ public ToastAlarm(IInterpreter interp) : base(interp)
 
         public override void Execute()
         {
-            SystemSounds.Exclamation.Play();
+            SystemSounds.Exclamation?.Play();
             App.Toast.ShowNotification("Avalon", this.Parameters, ToolTipIcon.Warning);
         }
 

src/Avalon.Client/MainWindow.Network.cs

@@ -7,6 +7,7 @@
  * @license           : MIT
  */
 
+using System.Media;
 using Avalon.Colors;
 using Avalon.Common.Models;
 using Avalon.Controls;
@@ -139,7 +140,14 @@ public void HandleLineReceived(object sender, string e)
             // One beep per line max, everything else is ignored.
             if (App.Settings.ProfileSettings.AnsiBeep && e.Contains('\a'))
             {
-                App.Beep?.Play();
+                if (App.Beep != null)
+                {
+                    App.Beep.Play();
+                }
+                else
+                {
+                    SystemSounds.Beep?.Play();
+                }
             }
 
             try