Canvas.Top Attached Property
Gets or sets the distance between the top of an element and the top of its parent Canvas.
Assembly: System.Windows (in System.Windows.dll)
XMLNS for XAML: Not mapped to an xmlns.
Dependency property identifier field: TopProperty
Negative values are permitted. A negative value places the origin of the element where is applied off-screen to the top side of the content area.
The value is interpreted by any immediate parent Canvas. If there are nested canvas elements, values for that do not come from immediate child elements are ignored. A Canvas can itself have a value, but the value does not apply on itself, rather it is interpreted by any parent Canvas, as in the nested scenario mentioned.