/// <summary>
/// 管道平行
/// </summary>
public void ElementRote()
{
	Document doc =this.ActiveUIDocument.Document;			
          Autodesk.Revit.UI.Selection.Selection sel =this.ActiveUIDocument.Selection;
          var eids =sel.GetElementIds();
          ElementSet els=new ElementSet();
          Line L1=null;
          Transaction ts1 = new Transaction(doc, "revit");
      	ts1.Start();
          foreach (var eid in eids)
          {
          	var elem=doc.GetElement(eid); 
              LocationCurve lCurve = elem.Location as LocationCurve;                
              if(L1==null)
              {
              	//设置基准管道
              	L1=lCurve.Curve as Line;
              }
              Line L2=lCurve.Curve as Line;
              //计算角度
              double deg=GetDegree(L2,L1);
              //管道旋转
              RotateColumn(doc,elem,L2,deg);               
          }
           ts1.Commit();
}