RectControl.TrueWindow
From Xojo Documentation
Read-Only Property (As Window )
Returns a reference to the actual enclosing Window.
Notes
TrueWindow walks up the window hierarchy and finds the actual enclosing window regardless of how deeply nested the RectControl or ContainerControl hierarchy is.
Window also has a TrueWindow property.
Example
This example accesses the TrueWindow and displays its Title property in a TextField.
TextField1.Value = Me.TrueWindow.Title