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author | E.Z. Hart <hartez@gmail.com> | 2016-09-27 12:11:57 -0600 |
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committer | E.Z. Hart <hartez@gmail.com> | 2016-09-27 12:11:57 -0600 |
commit | 33b60324383b5424339119e432137b6d7d898fa8 (patch) | |
tree | e7a96d5df501d4198105df5a099d29246895ef7f | |
parent | 87a79d14aa28bf77b70ad889a37964202ed4a302 (diff) | |
parent | 1a86ca598e7af954a584226b1a7761ef3675d39e (diff) | |
download | xamarin-forms-33b60324383b5424339119e432137b6d7d898fa8.tar.gz xamarin-forms-33b60324383b5424339119e432137b6d7d898fa8.tar.bz2 xamarin-forms-33b60324383b5424339119e432137b6d7d898fa8.zip |
Merge branch '2.3.3' of github.com:xamarin/Xamarin.Forms into 2.3.3
-rw-r--r-- | Xamarin.Forms.Core/BindingExpression.cs | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/Xamarin.Forms.Core/BindingExpression.cs b/Xamarin.Forms.Core/BindingExpression.cs index 5ce8cd87..71ba0512 100644 --- a/Xamarin.Forms.Core/BindingExpression.cs +++ b/Xamarin.Forms.Core/BindingExpression.cs @@ -409,6 +409,7 @@ namespace Xamarin.Forms class WeakPropertyChangedProxy { WeakReference _source, _listener; + internal WeakReference Source => _source; public WeakPropertyChangedProxy(INotifyPropertyChanged source, PropertyChangedEventHandler listener) { @@ -470,7 +471,13 @@ namespace Xamarin.Forms public void Subscribe(INotifyPropertyChanged handler) { - // If we're reapplying, we don't want to double subscribe + if (ReferenceEquals(handler, _listener?.Source?.Target)) + { + // Already subscribed + return; + } + + // Clear out the old subscription if necessary Unsubscribe(); _listener = new WeakPropertyChangedProxy(handler, _changeHandler); |