[iOS] Keep our native property listener around the same time we keep our proxy, check if we are KVO compliant before adding observer (#403)

1 files changed, 6 insertions, 3 deletions

diff --git a/Xamarin.Forms.Core/NativeBindingHelpers.cs b/Xamarin.Forms.Core/NativeBindingHelpers.cs
index 7e2db65b..e4cae7d9 100644
--- a/Xamarin.Forms.Core/NativeBindingHelpers.cs
+++ b/Xamarin.Forms.Core/NativeBindingHelpers.cs
@@ -43,8 +43,10 @@ namespace Xamarin.Forms
 				propertyChanged.PropertyChanged += (sender, e) => {
 					if (e.PropertyName != targetProperty)
 						return;
-				SetValueFromNative<TNativeView>(sender as TNativeView, targetProperty, bindableProperty);
-			};
+					SetValueFromNative<TNativeView>(sender as TNativeView, targetProperty, bindableProperty);
+					//we need to keep the listener around he same time we have the proxy
+					proxy.NativeINPCListener = propertyChanged;
+				};
 
 			if (binding != null && binding.Mode != BindingMode.OneWay)
 				SetValueFromNative(target, targetProperty, bindableProperty);
@@ -178,6 +180,7 @@ namespace Xamarin.Forms
 			public WeakReference<TNativeView> TargetReference { get; set; }
 			public IList<KeyValuePair<BindableProperty, BindingBase>> BindingsBackpack { get; } = new List<KeyValuePair<BindableProperty, BindingBase>>();
 			public IList<KeyValuePair<BindableProperty, object>> ValuesBackpack { get; } = new List<KeyValuePair<BindableProperty, object>>();
+			public INotifyPropertyChanged NativeINPCListener;
 
 			public BindableObjectProxy(TNativeView target)
 			{
@@ -193,4 +196,4 @@ namespace Xamarin.Forms
 			}
 		}
 	}
-}
\ No newline at end of file
+}