detect/WebViewControl.Avalonia/BaseControl.cs

using System;
using Avalonia.Controls;
using Avalonia.Interactivity;
using Avalonia.LogicalTree;

namespace WebViewControl {

    public abstract class BaseControl : Control {
        
        protected abstract void InternalDispose();

        protected override void OnAttachedToLogicalTree(LogicalTreeAttachmentEventArgs e) {
            if (e.Root is Window window) {
                // need to subscribe the event this way because close gets called after all elements get detached
                window.AddHandler(Window.WindowClosedEvent, (EventHandler<RoutedEventArgs>)OnHostWindowClosed);
            }
            base.OnAttachedToLogicalTree(e);
        }

        protected override void OnDetachedFromLogicalTree(LogicalTreeAttachmentEventArgs e) {
            if (e.Root is Window window) {
                window.RemoveHandler(Window.WindowClosedEvent, (EventHandler<RoutedEventArgs>)OnHostWindowClosed);
            }
            base.OnDetachedFromLogicalTree(e);
        }

        private void OnHostWindowClosed(object sender, RoutedEventArgs eventArgs) {
            ((Window)sender).RemoveHandler(Window.WindowClosedEvent, (EventHandler<RoutedEventArgs>)OnHostWindowClosed);
            InternalDispose();
        }
    }
}