Fix null dereferences

Author: TheCodeTraveler

src/CommunityToolkit.Maui.Core/Platform/StatusBar/StatusBar.android.cs

@@ -83,7 +83,9 @@ static void PlatformSetStyle(StatusBarStyle style)
 	static void SetStatusBarAppearance(Activity activity, bool isLightStatusBars)
 	{
 		var window = activity.GetCurrentWindow();
-		var windowController = WindowCompat.GetInsetsController(window, window.DecorView);
-		windowController.AppearanceLightStatusBars = isLightStatusBars;
+		if (WindowCompat.GetInsetsController(window, window.DecorView) is WindowInsetsControllerCompat windowController)
+		{
+			windowController.AppearanceLightStatusBars = isLightStatusBars;
+		}
 	}
 }

src/CommunityToolkit.Maui.MediaElement/Services/MediaControlsService.android.cs

@@ -22,7 +22,7 @@ sealed partial class MediaControlsService : Service
 	bool isDisposed;
 
 	PlayerNotificationManager? playerNotificationManager;
-	NotificationCompat.Builder? notification;
+	NotificationCompat.Builder? notificationBuilder;
 
 	public event EventHandler TaskRemoved
 	{
@@ -77,10 +77,10 @@ public override void OnRebind(Intent? intent)
 		StartForegroundServices();
 	}
 
-	[MemberNotNull(nameof(NotificationManager), nameof(notification))]
+	[MemberNotNull(nameof(NotificationManager), nameof(notificationBuilder))]
 	public void UpdateNotifications(in MediaSession session, in PlatformMediaElement mediaElement)
 	{
-		ArgumentNullException.ThrowIfNull(notification);
+		ArgumentNullException.ThrowIfNull(notificationBuilder);
 		ArgumentNullException.ThrowIfNull(NotificationManager);
 
 		var style = new MediaStyleNotificationHelper.MediaStyle(session);
@@ -89,8 +89,8 @@ public void UpdateNotifications(in MediaSession session, in PlatformMediaElement
 			SetLegacyNotifications(session, mediaElement);
 		}
 
-		notification.SetStyle(style);
-		NotificationManagerCompat.From(Platform.AppContext).Notify(1, notification.Build());
+		notificationBuilder.SetStyle(style);
+		NotificationManagerCompat.From(Platform.AppContext)?.Notify(1, notificationBuilder.Build());
 	}
 
 	[MemberNotNull(nameof(playerNotificationManager))]
@@ -152,26 +152,29 @@ static void CreateNotificationChannel(in NotificationManager notificationMnaMana
 		notificationMnaManager.CreateNotificationChannel(channel);
 	}
 
-	[MemberNotNull(nameof(notification), nameof(NotificationManager))]
+	[MemberNotNull(nameof(notificationBuilder), nameof(NotificationManager))]
 	void StartForegroundServices()
 	{
 		NotificationManager ??= GetSystemService(NotificationService) as NotificationManager ?? throw new InvalidOperationException($"{nameof(NotificationManager)} cannot be null");
-		notification ??= new NotificationCompat.Builder(Platform.AppContext, "1");
+		notificationBuilder ??= new NotificationCompat.Builder(Platform.AppContext, "1");
 
-		notification.SetSmallIcon(Resource.Drawable.media3_notification_small_icon);
-		notification.SetAutoCancel(false);
-		notification.SetForegroundServiceBehavior(NotificationCompat.ForegroundServiceImmediate);
-		notification.SetVisibility(NotificationCompat.VisibilityPublic);
+		notificationBuilder.SetSmallIcon(Resource.Drawable.media3_notification_small_icon);
+		notificationBuilder.SetAutoCancel(false);
+		notificationBuilder.SetForegroundServiceBehavior(NotificationCompat.ForegroundServiceImmediate);
+		notificationBuilder.SetVisibility(NotificationCompat.VisibilityPublic);
 
 		CreateNotificationChannel(NotificationManager);
 
 		if (OperatingSystem.IsAndroidVersionAtLeast(29))
 		{
-			StartForeground(1, notification.Build(), ForegroundService.TypeMediaPlayback);
+			if (notificationBuilder.Build() is Notification notification)
+			{
+				StartForeground(1, notification, ForegroundService.TypeMediaPlayback);
+			}
 		}
 		else
 		{
-			StartForeground(1, notification.Build());
+			StartForeground(1, notificationBuilder.Build());
 		}
 	}
 }

src/CommunityToolkit.Maui.MediaElement/Views/MauiMediaElement.android.cs

@@ -173,9 +173,12 @@ void SetSystemBarsVisibility()
 					| SystemUiFlags.Fullscreen
 					| SystemUiFlags.Immersive;
 			}
-
-			windowInsetsControllerCompat.Hide(barTypes);
-			windowInsetsControllerCompat.SystemBarsBehavior = WindowInsetsControllerCompat.BehaviorShowTransientBarsBySwipe;
+			
+			if(windowInsetsControllerCompat is not null)
+			{
+				windowInsetsControllerCompat.Hide(barTypes);
+				windowInsetsControllerCompat.SystemBarsBehavior = WindowInsetsControllerCompat.BehaviorShowTransientBarsBySwipe;
+			}
 
 		}
 		else
@@ -192,8 +195,12 @@ void SetSystemBarsVisibility()
 				currentWindow.DecorView.SystemUiFlags = (SystemUiFlags)defaultSystemUiVisibility;
 			}
 
-			windowInsetsControllerCompat.Show(barTypes);
-			windowInsetsControllerCompat.SystemBarsBehavior = WindowInsetsControllerCompat.BehaviorDefault;
+			if(windowInsetsControllerCompat is not null)
+			{
+				windowInsetsControllerCompat.Show(barTypes);
+				windowInsetsControllerCompat.SystemBarsBehavior = WindowInsetsControllerCompat.BehaviorDefault;
+			}
+			
 			WindowCompat.SetDecorFitsSystemWindows(currentWindow, true);
 		}
 	}

src/CommunityToolkit.Maui/PlatformConfiguration/AndroidSpecific/NavigationBar.android.cs

@@ -64,8 +64,10 @@ public static void MapNavigationStyleProperty(IPageHandler handler, IContentView
 		static void SetSystemNavigationBarAppearance(Activity activity, bool isLightSystemNavigationBars)
 		{
 			var window = activity.GetCurrentWindow();
-			var windowController = WindowCompat.GetInsetsController(window, window.DecorView);
-			windowController.AppearanceLightNavigationBars = isLightSystemNavigationBars;
+			if (WindowCompat.GetInsetsController(window, window.DecorView) is WindowInsetsControllerCompat insetsController)
+			{
+				insetsController.AppearanceLightNavigationBars = isLightSystemNavigationBars;
+			}
 		}
 	}