Revit API判断点与线是否相交

曲线有个curve.Distance(xyz)函数用来判断曲线与的距离。

[TransactionAttribute(Autodesk.Revit.Attributes.TransactionMode.Manual)]
public class cmdXyzLine : IExternalCommand
{
    public Result Execute(ExternalCommandData commandData, ref string messages, ElementSet elements)
    {
        UIApplication uiApp = commandData.Application;
        Document doc = uiApp.ActiveUIDocument.Document;
        Selection sel = uiApp.ActiveUIDocument.Selection;

        Transaction ts = new Transaction(doc, "http://revit.5d6d.com");
        ts.Start();

        //选取一直线，先风管吧。
        Duct duct = doc.GetElement(sel.PickObject(ObjectType.Element, "选取一风管")) as Duct;
        //选取一点
        XYZ xyz = sel.PickPoint("选取一点");
        //判断是否相交
        LocationCurve ductCurve = duct.Location as LocationCurve;
        TaskDialog.Show("distance", ductCurve.Curve.Distance(xyz).ToString());
        if (ductCurve.Curve.Distance(xyz) < 0.01)
            TaskDialog.Show("info", "相交");
        else
            TaskDialog.Show("info", "不相交");
        //风管上的点与风管曲线的距离
        TaskDialog.Show("dis", ductCurve.Curve.Distance(ductCurve.Curve.get_EndPoint(0)).ToString() + "米");

        ts.Commit();

        return Result.Succeeded;
    }
}

另外一个方法，比较专业，抽时间仔细研究研究：

/// <summary>
/// 两曲线通过轨迹相同且相连则可合并
/// </summary>
/// <param name="uiApp"></param>
/// <param name="c1"></param>
/// <param name="c2"></param>
/// <returns></returns>
public static Curve Combine2Curve(UIApplication uiApp, Curve c1, Curve c2)
{
    // 两曲线均为直线
    Line l1 = c1 as Line;
    if (l1 != null)
    {
        Line l2 = c2 as Line;
        if (l2 != null)
        {
            XYZ vt1 = LineAssistFunc.GetVector(l1);
            XYZ vt2 = LineAssistFunc.GetVector(l2);
            // 平行
            if (GeoUtil.IsParallel(vt1, vt2))
            {
                XYZ pts1 = l1.get_EndPoint(0);
                XYZ pte1 = l1.get_EndPoint(1);
                XYZ pts2 = l2.get_EndPoint(0);
                XYZ pte2 = l2.get_EndPoint(1);
                // 相连
                if (pts1.DistanceTo(pts2) < precision || pts1.DistanceTo(pte2) < precision ||
                    pte1.DistanceTo(pts2) < precision || pte1.DistanceTo(pte2) < precision)
                {
                    List<XYZ> arPts = new List<XYZ>();
                    arPts.Add(pts1);
                    arPts.Add(pte1);
                    arPts.Add(pts2);
                    arPts.Add(pte2);
                    GeoUtil.SortPointByDirect(uiApp, arPts, vt1);

                    Line nLine = uiApp.Application.Create.NewLineBound(arPts.First(), arPts.Last());
                    return nLine;
                }
            }
        }
    }

    // 两曲线均为弧线
    Arc a1 = c1 as Arc;
    if (a1 != null)
    {
        Arc a2 = c2 as Arc;
        if (a2 != null)
        {
            double r1 = a1.Radius;
            double r2 = a2.Radius;
            XYZ ptc1 = a1.Center;
            XYZ ptc2 = a2.Center;
            // 共线
            if (Math.Abs(r1 - r2) < precision && ptc1.DistanceTo(ptc2) < precision)
            {
                XYZ pts1 = a1.get_EndPoint(0);
                XYZ pte1 = a1.get_EndPoint(1);
                XYZ pts2 = a2.get_EndPoint(0);
                XYZ pte2 = a2.get_EndPoint(1);
                // 相连
                if (pts1.DistanceTo(pts2) < precision || pts1.DistanceTo(pte2) < precision ||
                    pte1.DistanceTo(pts2) < precision || pte1.DistanceTo(pte2) < precision)
                {
                    // 相交的点为ptOnArc点，其余两点为弧线的起终点
                    XYZ ptStart = null, ptEnd = null, ptOnArc = null;
                    if (pts1.DistanceTo(pts2) < precision)
                    {
                        ptStart = pte1;
                        ptEnd = pte2;
                        ptOnArc = pts1;
                    }
                    else if (pts1.DistanceTo(pte2) < precision)
                    {
                        ptStart = pte1;
                        ptEnd = pts2;
                        ptOnArc = pts1;
                    }
                    else if (pte1.DistanceTo(pts2) < precision)
                    {
                        ptStart = pts1;
                        ptEnd = pte2;
                        ptOnArc = pte1;
                    }
                    else if (pte1.DistanceTo(pte2) < precision)
                    {
                        ptStart = pts1;
                        ptEnd = pts2;
                        ptOnArc = pte1;
                    }

                    Arc nArc = uiApp.Application.Create.NewArc(ptStart, ptEnd, ptOnArc);
                    return nArc;
                }
            }
        }
    }

    return null;
}

from:http://revit.5d6d.com/thread-1379-1-1.html