如何在Revit中以编程方式延伸管道

using Autodesk.Revit.DB;
using Autodesk.Revit.UI;

public class PipeExtender : IExternalCommand
{
    public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)
    {
        UIApplication uiApp = commandData.Application;
        Document doc = uiApp.ActiveUIDocument.Document;

        // 获取选中的管道
        Reference pickedRef = uiApp.ActiveUIDocument.Selection.PickObject(ObjectType.Element, "Select a pipe to extend");
        Pipe pipe = doc.GetElement(pickedRef) as Pipe;

        if (pipe == null)
        {
            message = "Please select a valid pipe.";
            return Result.Failed;
        }

        // 设置延伸的目标点
        XYZ targetPoint = GetTargetPoint(pipe); // 这里需要实现获取目标点的逻辑

        // 创建新的管道段
        Pipe newPipeSegment = CreateNewPipeSegment(pipe, targetPoint); // 这里需要实现创建新管道段的逻辑

        // 替换原管道
        ReplaceElement(doc, pipe, newPipeSegment);

        return Result.Succeeded;
    }

    private XYZ GetTargetPoint(Pipe pipe)
    {
        // 实现获取目标点的逻辑，例如通过用户交互选择或计算得出
        // ...
        return new XYZ(0, 0, 0); // 示例返回值，需根据实际情况修改
    }

    private Pipe CreateNewPipeSegment(Pipe originalPipe, XYZ targetPoint)
    {
        // 实现创建新管道段的逻辑
        // ...
        return null; // 示例返回值，需根据实际情况修改
    }

    private void ReplaceElement(Document doc, Element oldElement, Element newElement)
    {
        // 实现替换元素的逻辑
        // ...
    }
}