Software Developer's Kit - ChemDraw

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AngularSize Property
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Member of ChemDraw Control.Arrow

Sets and returns the angular size of this arrow.  

Property type

Read-write property


Visual Basic
Public Property AngularSize() As Double

Return Type



This property measures the angle subtended by the curve of the arrow measured from its center of curvature.

The arrow angle is measured in degrees, with decimals and sign. Straight arrows have an AngularSize=0. Curved arrows have AngularSize<>0. Negative values will curve the arrow clockwise, positive values will curve the arrow anticlockwise. 

For a curved arrow (AngularSize<>0) the End  point is the center of the arc.
For a straight arrow (AngularSize=0) the End point is positioned at the tail point.

If a straight arrow (in the drawing with a dashed line) is changed to Angular Size = 180 the arrow will curve forming half a circle (bold arrow) whose center point will be the arrow´s original End point. The original End point of the arrow becomes the center of the curve. The original Start  point remains the same.

In Control Version 10.0, when first drawn, a straight arrow returns AngularSize as 0.5, which is meaningless. If you set the angular size to 0.5 for a straight arrow, it almost disappears because it is a very small angle.

All arrows, except retrosynthetic arrows (Shaft Spacing>0 & ArrowHeadType=kCDArrowHeadTypeAngle), can be made into arcs.


'Declares variable vArrow
 Dim vArrow As ChemDrawControl10Ctl.Arrow
'Checks that there is an arrow loaded in the variable
 If  Selection.Arrows.Count < 1 Then
     Exit Sub
 End If

 Private Sub cmdAngularSize_click()
    'Curves the arrow 90 degrees anticlockwise 
     vArrow.AngularSize = 90
    'Curves the arrow 180 degrees clockwise
     vArrow.AngularSize = -180
 End Sub

See Also