McNeel Wiki

public static Rhino.Commands.Result AddAnnotationText(Rhino.RhinoDoc doc)
{
  Rhino.Geometry.Point3d pt = new Rhino.Geometry.Point3d(10, 0, 0);
  const string text = "Hello RhinoCommon";
  const double height = 2.0;
  const string font = "Arial";
  Rhino.Geometry.Plane plane = doc.Views.ActiveView.ActiveViewport.ConstructionPlane();
  plane.Origin = pt;
  Guid id = doc.Objects.AddText(text, plane, height, font, false, false);
  if( id != Guid.Empty )
  {
    doc.Views.Redraw();
    return Rhino.Commands.Result.Success;
  }
  return Rhino.Commands.Result.Failure;
}

Public Shared Function AddAnnotationText(ByVal doc As Rhino.RhinoDoc) As Rhino.Commands.Result
  Dim pt As New Rhino.Geometry.Point3d(10, 0, 0)
  Const text As String = "Hello RhinoCommon"
  Const height As Double = 2.0
  Const font As String = "Arial"
  Dim plane As Rhino.Geometry.Plane = doc.Views.ActiveView.ActiveViewport.ConstructionPlane()
  plane.Origin = pt
  Dim id As Guid = doc.Objects.AddText(text, plane, height, font, False, False)
  If id <> Guid.Empty Then
    doc.Views.Redraw()
    Return Rhino.Commands.Result.Success
  End If
  Return Rhino.Commands.Result.Failure
End Function

import Rhino
import scriptcontext
import System.Guid
 
def AddAnnotationText():
    pt = Rhino.Geometry.Point3d(10, 0, 0)
    text = "Hello RhinoCommon"
    height = 2.0
    font = "Arial"
    plane = scriptcontext.doc.Views.ActiveView.ActiveViewport.ConstructionPlane()
    plane.Origin = pt
    id = scriptcontext.doc.Objects.AddText(text, plane, height, font, False, False)
    if id!=System.Guid.Empty:
        scriptcontext.doc.Views.Redraw()
        return Rhino.Commands.Result.Success
    return Rhino.Commands.Result.Failure
 
 
if __name__=="__main__":
    AddAnnotationText()