This question has been answered here and elsewhere many times.
Please research before posting!
Normally, you can simply set the start and end point of the beam location line, as demonstrated by the FrameBuilder SDK sample:
R:\Samples\FrameBuilder\CS\FrameBuilder.cs(285): /// <summary> /// set location line to the Element /// </summary> /// <param name="elem">goal Element</param> /// <param name="startPnt">start point of the line</param> /// <param name="endPnt">end point of the line</param> /// <returns>is successful</returns> private bool SetLocationLine(ModelElement elem, XYZ startPnt, XYZ endPnt) { LocationCurve elemCurve = elem.Location as LocationCurve; if (null != elemCurve && !elemCurve.IsReadOnly) { try { Line line = m_appCreator.NewLineBound(ref startPnt, ref endPnt); elemCurve.Curve = line; return true; } catch (Exception ex) { Debug.WriteLine(ex.ToString()); } } return false; }
Cheers,
Jeremy