FrameworkElement Loaded doesn't work well

[limeniye]

I created some element and subscribed to the ⚡Loaded action

<Page x:Class="SizeChangingDemonstrate.MainPage" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

    <Grid x:Name="grid" Background="#1e1e1e"/>
    
</Page>

        public MainPage()
        {
            this.InitializeComponent();

            System.Diagnostics.Debug.WriteLine($"grid start width is {grid.ActualWidth}");
            grid.Loaded += (s, e) =>
            {
                System.Diagnostics.Debug.WriteLine($"__________grid loaded__________");
                System.Diagnostics.Debug.WriteLine($"grid current width is {grid.ActualWidth}");
            };
        }

I expect next result:
ActualWidth must have some value. For example -- 500

But the real result:
ActualWidth is 0

UWP debug result

grid start width is 0
__________grid loaded__________
grid current width is 825

WPF Skia result

grid start width is 0
__________grid loaded__________
grid current width is 0

• UWP
• Android
• WASM
• WPF Skia

[limeniye]

I did temporary realization, but this code too bad and I want to know how can I realize it normally:

        public MainPage()
        {
            this.InitializeComponent();

            System.Diagnostics.Debug.WriteLine($"grid start width is {grid.ActualWidth}");
            grid.Foo(() => 
            {
                System.Diagnostics.Debug.WriteLine($"__________grid loaded__________");
                System.Diagnostics.Debug.WriteLine($"grid current width is {grid.ActualWidth}");
            });
        }

    public static class UnoTemprarySizeInitializationHelper
    {
        /// <summary>
        /// Performs an action after size initizalizion.
        /// </summary>
        /// <param name="execute">Some action after size will iti</param>
        public static void Foo(this FrameworkElement element, Action execute)
        {
            SizeChangedEventHandler tempraryDelegate = null;
            tempraryDelegate = delegate (object s, SizeChangedEventArgs e)
            {
                execute();
                element.SizeChanged -= tempraryDelegate;
            };

            element.SizeChanged += tempraryDelegate;
            
        }
    }

[jeromelaban]

Uno is having subtle differences with WinUI with regards to the way ActualWidth is updated, and to get an accurate value, try using the LayoutUpdated event instead.

[limeniye]

@jeromelaban Yes, you'r right! Thank you for your answer.