[iOS] Fix usage of iOS11 api

Xamarin.Forms.Platform.iOS/PlatformRenderer.cs

@@ -47,7 +47,7 @@ public override UIInterfaceOrientationMask GetSupportedInterfaceOrientations()
 			{
 				return ChildViewControllers[0].GetSupportedInterfaceOrientations();
 			}
-			
+
 			return base.GetSupportedInterfaceOrientations();
 		}
 
@@ -104,7 +104,8 @@ public override void ViewDidLoad()
 		{
 			base.ViewDidLoad();
 			SetNeedsStatusBarAppearanceUpdate();
-			SetNeedsUpdateOfHomeIndicatorAutoHidden();
+			if (Forms.IsiOS11OrNewer)
+				SetNeedsUpdateOfHomeIndicatorAutoHidden();
 		}
 
 		public override UIViewController ChildViewControllerForStatusBarStyle()
@@ -139,7 +140,7 @@ public override UIInterfaceOrientation PreferredInterfaceOrientationForPresentat
 			}
 			return base.PreferredInterfaceOrientationForPresentation();
 		}
-		
+
 		public override UIViewController ChildViewControllerForStatusBarHidden()
 		{
 			return (UIViewController)Platform.GetRenderer(this.Platform.Page);
@@ -198,7 +199,8 @@ public override void ViewDidLoad()
 		{
 			base.ViewDidLoad();
 			SetNeedsStatusBarAppearanceUpdate();
-			SetNeedsUpdateOfHomeIndicatorAutoHidden();
+			if (Forms.IsiOS11OrNewer)
+				SetNeedsUpdateOfHomeIndicatorAutoHidden();
 		}
 	}
 }

Xamarin.Forms.Platform.iOS/Renderers/NavigationRenderer.cs

@@ -231,7 +231,8 @@ public override void ViewDidLoad()
 			UpdateBarTextColor();
 			UpdateUseLargeTitles();
 			UpdateHideNavigationBarSeparator();
-			SetNeedsUpdateOfHomeIndicatorAutoHidden();
+			if (Forms.IsiOS11OrNewer)
+				SetNeedsUpdateOfHomeIndicatorAutoHidden();
 
 			// If there is already stuff on the stack we need to push it
 			navPage.Pages.ForEach(async p => await PushPageAsync(p, false));
@@ -724,9 +725,9 @@ internal async Task UpdateFormsInnerNavigation(Page pageBeingRemoved)
 		{
 			if (NavPage == null)
 				return;
-			if (_ignorePopCall) 
+			if (_ignorePopCall)
 				return;
-			
+
 			_ignorePopCall = true;
 			if (Element.Navigation.NavigationStack.Contains(pageBeingRemoved))
 				await (NavPage as INavigationPageController)?.RemoveAsyncInner(pageBeingRemoved, false, true);
@@ -1347,7 +1348,7 @@ public override void LayoutSubviews()
 
 								break;
 							}
-							else if(view.Class.Name == "UINavigationItemButtonView")
+							else if (view.Class.Name == "UINavigationItemButtonView")
 							{
 								if (view.Subviews.Length == 0)
 									NavBarLabel = null;
@@ -1475,7 +1476,7 @@ public override void LayoutSubviews()
 					if (_child.Element.Bounds != layoutBounds)
 						Layout.LayoutChildIntoBoundingRegion(_child.Element, layoutBounds);
 				}
-				else if(_icon != null && Superview != null)
+				else if (_icon != null && Superview != null)
 				{
 					_icon.Center = new PointF(Superview.Frame.Width / 2 - Frame.X, Superview.Frame.Height / 2);
 				}

Xamarin.Forms.Platform.iOS/Renderers/PageRenderer.cs

@@ -171,7 +171,8 @@ public override void ViewDidAppear(bool animated)
 
 			_appeared = true;
 			UpdateStatusBarPrefersHidden();
-			SetNeedsUpdateOfHomeIndicatorAutoHidden();
+			if(Forms.IsiOS11OrNewer)
+				SetNeedsUpdateOfHomeIndicatorAutoHidden();
 
 			if (Element.Parent is CarouselPage)
 				return;
@@ -439,7 +440,7 @@ IEnumerable<UIView> ViewAndSuperviewsOfView(UIView view)
 
 		void UpdateHomeIndicatorAutoHidden()
 		{
-			if (Element == null)
+			if (Element == null || !Forms.IsiOS11OrNewer)
 				return;
 
 			SetNeedsUpdateOfHomeIndicatorAutoHidden();

Xamarin.Forms.Platform.iOS/Renderers/PhoneMasterDetailRenderer.cs

@@ -336,7 +336,8 @@ void UpdateMasterDetailContainers()
 			_detailController.AddChildViewController(detailRenderer.ViewController);
 
 			SetNeedsStatusBarAppearanceUpdate();
-			SetNeedsUpdateOfHomeIndicatorAutoHidden();
+			if (Forms.IsiOS11OrNewer)
+				SetNeedsUpdateOfHomeIndicatorAutoHidden();
 		}
 
 		void UpdateLeftBarButton()