If you want to access your ItemsControl in the UserControl code-behind file, you need to give the ItemsControl a name like:
<itemscontrol x:name="MyItemsControl Items=" path="Items}"" xmlns:x="#unknown" />
Then use this name to access the ItemsControl:
foreach(var item in MyItemsControl.Items)
{
}
If you want to access the ItemsControl from outside of the UserControl you first need to define a property on your UserControl and than use that property to access the ItemsControl.
Uroš