Why Doesn't My ObservableCollection Update When Item Properties Change?

ObserVableCollection Update: Discuss and solve the solution

When using

in the MVVM application, the change of individual set items must be triggered. However, users may encounter the failure of these notifications, causing data binding controls to respond without response. This article discusses the root cause of this issue and provides a comprehensive solution.

ObservableCollection Detailed problem

The problem appeared in the collection item itself to achieve , but

did not observe these changes inside. Therefore, the attributes of the modified items will not cause changes notice at the set level, and the data binding cannot perceive these modifications.

INotifyPropertyChanged Solution: Custom ObservableCollection ObservableCollection

In order to solve this limit, this article introduces custom classes. Such extensions have and forced all items must implement constraints. It is important that it rewrite the

event processing program so that the attribute change processing program is attached to the new item and is separated from the old item to ensure that all attribute changes will trigger the collection level notification.

TrulyObservableCollection TrulayobServableCollection's implementation ObservableCollection INotifyPropertyChanged CollectionChanged Class treatment The following operations:

Add item: When the item is added to the collection, it will subscribe to the

event to detect attributes to change.

TrulyObservableCollection Moving item:

When the item is removed, it will cancel the

incident subscribed to the item.
• Attribute change: When the attributes of the item are changed, the set will cause PropertyChanged to effectively refresh all binding.
• How to use PropertyChanged
To use , just replace the conventional
• to . When the attributes in the set change are changed, your binding will be automatically updated. NotifyCollectionChangedEventArgs Conclusion

When using the item of , solves the problem of missed changes in . By actively listening to the attribute changes in the set, it ensures that all data binding remains to the latest, thereby improving the response capacity and accuracy of the data binding control in the MVVM application.

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