Leaders are associated with their annotation so that when the annotation moves, the endpoint of the leader moves with it.
As you move text and feature control frame annotation, the final leader line segment alternates between attaching to the left side and to the right side of the annotation according to the relation of the annotation to the penultimate (second to last) point of the leader. If the midpoint of the annotation is to the right of the penultimate leader point, then the leader attaches to the right; otherwise, it attaches to the left.
Removing either object from the drawing using either the Delete, Add (to add a block), or WBlock method will break associativity. If the leader and its annotation are copied together in a single operation, the new copy is associative. If they are copied separately, they will not be associative. If associativity is broken for any reason, for example, by copying only the Leader object or by erasing the annotation, the hook line will be removed from the leader.
This example creates an MText object. A leader line is then created using the MText object as its annotation.
Sub Ch5_AddAnnotation()
Dim leaderObj As AcadLeader
Dim mtextObj As AcadMText
Dim points(0 To 8) As Double
Dim insertionPoint(0 To 2) As Double
Dim width As Double
Dim leaderType As Integer
Dim annotationObject As Object
Dim textString As String, msg As String
' Create the MText object in model space
textString = "Hello, World."
insertionPoint(0) = 5
insertionPoint(1) = 5
insertionPoint(2) = 0
width = 2
Set mtextObj = ThisDrawing.ModelSpace. _
AddMText(insertionPoint, width, textString)
' Data for Leader
points(0) = 0: points(1) = 0: points(2) = 0
points(3) = 4: points(4) = 4: points(5) = 0
points(6) = 4: points(7) = 5: points(8) = 0
leaderType = acLineWithArrow
' Create the Leader object in model space and associate
' the MText object with the leader
Set annotationObject = mtextObj
Set leaderObj = ThisDrawing.ModelSpace. _
AddLeader(points, annotationObject, leaderType)
ZoomAll
End Sub