Public ReadOnly Property DrawingSurface As Control

Dim instance As AnnotationModeEventArgs
Dim value As Control
 
value = instance.DrawingSurface

public Control DrawingSurface {get;}

private void fpSpread1AnnotationModeStarting(object sender, FarPoint.Win.Spread.AnnotationModeEventArgs e) 
{ 
     e.DrawingSurface.BackColor = Color.Cornsilk; 
}

Private Sub FpSpread1AnnotationModeStarting(ByVal sender As Object, ByVal e As FarPoint.Win.Spread.AnnotationModeEventArgs)
    e.DrawingSurface.BackColor = Color.Cornsilk
End Sub