https://github.com/shweaver-msft/loadedunloadedevents

FrameworkElement Load/Unload event propagation normalization
https://github.com/shweaver-msft/loadedunloadedevents

uwp xaml

Last synced: 24 days ago
JSON representation

FrameworkElement Load/Unload event propagation normalization

• Host: GitHub
• URL: https://github.com/shweaver-msft/loadedunloadedevents
• Owner: shweaver-MSFT
• License: mit
• Created: 2019-09-20T00:08:17.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2019-09-20T16:17:04.000Z (over 5 years ago)
• Last Synced: 2024-11-13T05:22:20.471Z (3 months ago)
• Topics: uwp, xaml
• Language: C#
• Homepage:
• Size: 23.4 KB
• Stars: 0
• Watchers: 2
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

        
# LoadedUnloadedEvents

In UWP XAML, it is possible for the Loaded and Unloaded events of a FrameworkElement to propagate in a different order than they occurred.

A common instance is when an element is disconnected from the VisualTree and re-inserted somewhere else.

Without additional checks, any code that relies on those events bubbling in a consistent order will be at risk of breaking.

This solution offers a simple workaround, in the form of the `ElementLoadNormalizer.cs`

Simply add the `ElementLoadNormalizer` to your application and adopt the pattern below to ensure the correct processing order:

```

public MainPage()

{

    InitializeComponent();

    myElement.Loaded += OnLoaded;

    myElement.Unloaded += OnUnloaded;

    // Wire up the loading event extensions

    myElement.ExtendLoadingEvents();

}

private void OnUnloaded(object sender, RoutedEventArgs e)

{

    if (sender is FrameworkElement element)

    {

        var lastLoadedArgs = element.GetLastLoadedEventArgs();

        if (lastLoadedArgs != null)

        {

            HandleLoaded(sender, lastLoadedArgs);

        }

        

        HandleUnloaded(sender, e);

    }

}

private void OnLoaded(object sender, RoutedEventArgs e)

{

    if (sender is FrameworkElement element)

    {

        HandleLoaded(sender, e);

    

        var lastUnloadedArgs = element.GetLastUnloadedEventArgs();

        if (lastUnloadedArgs != null)

        {

            HandleUnloaded(sender, lastUnloadedArgs);

        }

    }

}

private void HandleUnloaded(object sender, RoutedEventArgs e) { ... }

private void HandleLoaded(object sender, RoutedEventArgs e) { ... }

```