Preproducing Microsoft.Maui.Controls.Element: Warning: The RealParent on Microsoft.Maui.Controls.*** has been Garbage Collected....

gistfile1.txt

Warnings:
- Microsoft.Maui.Controls.Element: Warning: CommonMaui.Presentation.Views.Diagnostics.DiagnosticLabel is already a child of Microsoft.Maui.Controls.VerticalStackLayout. Remove CommonMaui.Presentation.Views.Diagnostics.DiagnosticLabel from Microsoft.Maui.Controls.VerticalStackLayout before adding to Microsoft.Maui.Controls.VerticalStackLayout.

Followed by:
- Microsoft.Maui.Controls.Element: Warning: The RealParent on CommonMaui.Presentation.Views.Diagnostics.DiagnosticLabel has been Garbage Collected. This should never happen. Please log a bug: https://github.com/dotnet/maui

In my scenario I have a custom Label:

	public DiagnosticLabel(string path)
	{
		var target = path.Split('.').Last();
		Span prefix = new() { Text = target, TextColor = Colors.Blue, FontAttributes = FontAttributes.Bold };
		Span delimiter = new() { Text = " : " };
		Span data = new() { TextColor = Colors.Wheat };
		data.SetBinding(targetProperty: Span.TextProperty, binding: new Binding(path: path));
		FormattedText = new() { Spans = { prefix, delimiter, data } };
	}

Which is in turn used in a custom Data Template:

public class BleDeviceDiagnosticItemDataTemplate : DataTemplate
{
	public BleDeviceDiagnosticItemDataTemplate()
	{
		LoadTemplate = static () =>
		{
			DiagnosticLabel idLabel = new(nameof(BleDevice.Id));
			
			ScrollView scrollView = new() {	Content = new VerticalStackLayout	{	Children = { idLabel } };
			var copy = new VerticalStackLayout { Children = { idLabel } };   // creating this, even when unused causes Warning

			return scrollView;
		};
	}
}

**** Note: the variable "copy" even while unused, will causes the Warning ****, ie. Remove it and there is no Warning...


The above is used in what I call a View Selector:

public class BleDiagnosticsViewSelector
{
	public View LoadView(object bindingContext)
	{
		return bindingContext switch
		{
			null => ControlTemplateLoadTemplate<NoDeviceDataTemplate>(),
			BleDeviceItem => ControlTemplateLoadTemplate<BleDeviceDiagnosticItemDataTemplate>(),
			_ => throw new ArgumentOutOfRangeException(nameof(bindingContext), bindingContext, null)
		};
	}

	private static View ControlTemplateLoadTemplate<TDt>() where TDt : DataTemplate, new() => (View)new ContentView { ControlTemplate = new() { LoadTemplate = new TDt().LoadTemplate } }.ControlTemplate.LoadTemplate();
}


Which in turn is used by a custom ContentPage in order to populate and repopulate the Page with different Content:

internal class BleBasicDeviceDetailsPage : ContentPage
{
	private readonly BleDiagnosticsViewSelector _viewSelector = new();

	internal void SetContent(BleDeviceItem bleDeviceItem) => Content = _viewSelector.LoadView(someBindingContextForDataTemplate);
}


And at some point when this Content is set, or set agian... the warning will spawn AS LONG AS A CONTROL VARIABLE WITH THE CUSTOM LABEL IS MERELY CREATED as indicated above