https://learn.microsoft.com/en-us/uwp/api/windows.ui.xaml.controls.primitives.gridviewitemtemplatesettings?view=winrt-28000&redirectedfrom=MSDN
GridViewItemTemplateSettings Class (Windows.UI.Xaml.Controls.Primitives) - Windows apps | Microsoft...
Provides calculated values that can be referenced as TemplatedParent sources when defining templates for a GridView control. Not intended for general use.
classwindowsuixamlcontrols