Specifies whether a layer is in use.
Supported platforms: Windows only
Read-only: Yes
Type: Boolean
This property specifies whether a layer is in use when the GenerateUsageData method is called.
VBA:
Sub Example_Used()
    ' This example provides usage information for the layers
    ' in a drawing
    Dim MyLayers As AcadLayers
    Set MyLayers = ThisDrawing.Layers
    MyLayers.GenerateUsageData
    
    Dim MyLayerObj As AcadLayer
    For Each MyLayerObj In ThisDrawing.Layers
        MyLayerObj.Description = "Test"
        MsgBox (MyLayerObj.Used)
    Next MyLayerObj
End Sub
Visual LISP:
(vl-load-com)
(defun c:Example_Used()
    ;; This example provides usage information for the layers
    ;; in a drawing
    (setq acadObj (vlax-get-acad-object))
    (setq doc (vla-get-ActiveDocument acadObj))
    (setq MyLayers (vla-get-Layers doc))
    (vla-GenerateUsageData MyLayers)
    (vlax-for MyLayerObj (vla-get-Layers doc)
        (alert (strcat "Layer " (vla-get-Name MyLayerObj) (if (= (vla-get-Used MyLayerObj) :vlax-true) " is used." " is not used.")))
    )
)