GetTemplateChild returns null when entry not in layout (e.g. VerticalStackLayout)

Open vsfeedback opened this issue 1 year ago • 1 comments

This issue has been moved from a ticket on Developer Community.

When a custom control has a control template with only the entry, the function GetTemplateChild returns null and that results in a null reference exception. When the control template holds a VerticalStackLayout with the same entry the function GetTemplateChild returns the entry.

This does not work:

	<ContentView.ControlTemplate>
		<ControlTemplate>
			<ctrls:CustomEntry x:Name="entry"
							   InputInfo="{TemplateBinding NumberInfo}" />
		</ControlTemplate>
	</ContentView.ControlTemplate>

This works:

	<ContentView.ControlTemplate>
		<ControlTemplate>
			<VerticalStackLayout>
				<ctrls:CustomEntry x:Name="entry"
								   InputInfo="{TemplateBinding NumberInfo}" />
			</VerticalStackLayout>
		</ControlTemplate>
	</ContentView.ControlTemplate>

This code returns null in the first case:

	protected override void OnApplyTemplate()
	{
		base.OnApplyTemplate();
		entry = (CustomEntry)GetTemplateChild("entry");
	}

To make it very clear, all I have changed is add the VerticalStackLayout to solve the null reference exception. All the other code has not been changed. I do not like adding layout elements without any function. I think this is a bug.