写一个在revit 2016软件中C#写的选取cad链接文件的图层中线的代码

以下是在Revit 2016软件中，使用C#编写的选取CAD链接文件的图层中线的代码：

// 获取CAD链接文件的图层中线
public void GetCADLinkedFileLayerLines(Document doc, string cadFileName, string layerName)
{
    // 获取CAD链接文件实例
    FilteredElementCollector collector = new FilteredElementCollector(doc);
    collector.OfCategory(BuiltInCategory.OST_RvtLinks);
    Element linkedFile = collector.FirstElement();
    RevitLinkInstance linkInstance = linkedFile as RevitLinkInstance;

    // 获取CAD链接文件的图形文档
    Document linkDoc = linkInstance.GetLinkDocument();
    if (linkDoc == null)
        return;

    // 获取CAD链接文件的图层
    LayerTable layerTable = linkDoc.Database.LayerTableId.GetObject(OpenMode.ForRead) as LayerTable;
    if (layerTable == null)
        return;

    ObjectId layerId = ObjectId.Null;
    foreach (ObjectId id in layerTable)
    {
        LayerTableRecord layer = id.GetObject(OpenMode.ForRead) as LayerTableRecord;
        if (layer != null && layer.Name.Equals(layerName))
        {
            layerId = id;
            break;
        }
    }

    if (layerId == ObjectId.Null)
        return;

    // 获取CAD链接文件的图层中的所有线
    BlockTable blockTable = linkDoc.Database.BlockTableId.GetObject(OpenMode.ForRead) as BlockTable;
    if (blockTable == null)
        return;

    BlockTableRecord blockTableRecord = blockTable[BlockTableRecord.ModelSpace].GetObject(OpenMode.ForRead) as BlockTableRecord;
    if (blockTableRecord == null)
        return;

    foreach (ObjectId id in blockTableRecord)
    {
        Entity entity = id.GetObject(OpenMode.ForRead) as Entity;
        if (entity != null && entity.LayerId.Equals(layerId) && entity is Line)
        {
            Line line = entity as Line;
            // 在Revit中创建与CAD链接文件图层中线相对应的Revit线
            XYZ startPoint = new XYZ(line.StartPoint.X, line.StartPoint.Y, line.StartPoint.Z);
            XYZ endPoint = new XYZ(line.EndPoint.X, line.EndPoint.Y, line.EndPoint.Z);
            Line revitLine = Line.CreateBound(startPoint, endPoint);
            // 将Revit线添加到文档中
            using (Transaction trans = new Transaction(doc))
            {
                trans.Start("Create Line");
                doc.Create.NewDetailCurve(doc.ActiveView, revitLine);
                trans.Commit();
            }
        }
    }
}

该代码首先获取CAD链接文件实例，然后获取CAD链接文件的图形文档和图层。接着，它遍历CAD链接文件的图层中的所有线，并在Revit中创建与CAD链接文件图层中线相对应的Revit线，并将其添加到文档中。