Turned-off layers are regenerated with the drawing but are not displayed or plotted.
By turning layers off, you avoid regenerating the drawing every time you thaw a layer. When you turn a layer on that has been turned off, AutoCAD redraws the objects on that layer.
To turn layers on and off, use the LayerOn property. If you input a value of TRUE to this property, the layer is turned on. If you input a value of FALSE, the layer is turned off.
This example creates a new layer, adds a circle to the layer, then turns off the layer so that the circle is no longer visible.
Sub Ch4_LayerInvisible() ' Create a circle Dim circleObj As AcadCircle Dim center(0 To 2) As Double Dim radius As Double center(0) = 2: center(1) = 2: center(2) = 0 radius = 1 Set circleObj = ThisDrawing.ModelSpace.AddCircle(center, radius) ' Create a new layer called "ABC" Dim layerObj As AcadLayer Set layerObj = ThisDrawing.Layers.Add("ABC") ' Assign the circle to the "ABC" layer circleObj.Layer = "ABC" circleObj.Update ' Turn off layer "ABC" layerObj.LayerOn = False ThisDrawing.Regen acActiveViewport End Sub