这是一期Revit二次开发小案例（自动布置支吊架）

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Data;
using Autodesk.Revit;
using Autodesk.Revit.UI;
using Autodesk.Revit.UI.Selection;
using Autodesk.Revit.DB;
using Autodesk.Revit.DB.Architecture;
using Autodesk.Revit.DB.Mechanical;
using Autodesk.Revit.DB.Plumbing;
using Autodesk.Revit.DB.Electrical;
using Autodesk.Revit.ApplicationServices;
using System.Data.SqlClient;
using Autodesk.Revit.Creation;
using Autodesk.Revit.DB.Structure;//之前没有记得复制啊
namespace zpx123
{
    [Autodesk.Revit.Attributes.Transaction(Autodesk.Revit.Attributes.TransactionMode.Manual)]
    [Autodesk.Revit.Attributes.Regeneration(Autodesk.Revit.Attributes.RegenerationOption.Manual)]
    [Autodesk.Revit.Attributes.Journaling(Autodesk.Revit.Attributes.JournalingMode.NoCommandData)]
    public class Class1 : IExternalCommand
    {
        public Autodesk.Revit.UI.Result Execute(ExternalCommandData commandData, ref string message, Autodesk.Revit.DB.ElementSet elements)
        {
            //创建应用程序对象
            Autodesk.Revit.ApplicationServices.Application app = commandData.Application.Application;
            //创建文档对象
            Autodesk.Revit.DB.Document doc = commandData.Application.ActiveUIDocument.Document;
            //创建应用程序对象
            Autodesk.Revit.UI.UIApplication uiapp = commandData.Application;
            //创建文档对象
            Autodesk.Revit.UI.UIDocument uiDoc = uiapp.ActiveUIDocument;
            //开始事务
            Transaction ts = new Transaction(doc, "支吊架布置");
            ts.Start();

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace zpx123
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        public void textBox1_TextChanged(object sender, EventArgs e)
        {
            string str = textBox1.Text;
        }
        private void button1_Click(object sender, EventArgs e)
        {
            this.DialogResult = DialogResult.OK;
        }
        public string Number
        {
            get { return textBox1.Text; }//获得文本框里返回的值
        }
        private void Form1_Load(object sender, EventArgs e)
        {
        }
    }
}

           double number = 0;
            int number1 = 0;
            zpx123.Form1 form = new zpx123.Form1();
            form.ShowDialog();
            if (form.DialogResult == DialogResult.OK)
            {
                string str = form.Number;
              //为了防止用户乱输入发生错误，我习惯踹一脚
             try
                {
                    number1 = Convert.ToInt32(str);
                    number = number1/304.8;
                }
                catch
                {
                    MessageBox.Show("请输入正确的数字");
                }
            }
//通过以上这些就可以获得用户输入的数值了
            ElementId id = null;
            FilteredElementCollector faa = new FilteredElementCollector(doc);
            faa.OfClass(typeof(FamilyInstance));//收集族类型
            foreach (FamilyInstance fa in faa)
            {
                if (fa.GetParameters("族与类型")[0].AsValueString().Contains("支吊架"))
                {
                    id = fa.Symbol.Id;
                }
            }
            FamilySymbol fas = doc.GetElement(id) as FamilySymbol;
            Selection ree = uiDoc.Selection;
            Reference re = ree.PickObject(ObjectType.Element);
            Element elem = doc.GetElement(re);
            Pipe pipe = elem as Pipe;
            LocationCurve curve = pipe.Location as LocationCurve;
            XYZ start = curve.Curve.GetEndPoint(0);//获取管道的起点
            XYZ end = curve.Curve.GetEndPoint(1);//获得管道的终点
            double a = start.X ;
            double b = start.Y ;
            double zz = start.Z ;
            double c = end.X ;
            double d = end.Y ;
            //以上是获得管道起点和终点的xyz的值
            double xy = start.DistanceTo(end) ;//求距离
            int gs = (int)((xy / number));//求要放几个支吊架
           double y = (number * (d - b)) / Math.Sqrt((c - a) * (c - a) + (d - b) * (d - b)) ;
           double x = (number * (c - a)) / Math.Sqrt((c - a) * (c - a) + (d - b) * (d - b)) ;
           //以上为数学公式
            List<FamilyInstanceCreationData> listt = new List<FamilyInstanceCreationData>();
            //用来存储一系列的管道坐标的集合
            for (double j = 0; j < gs; j ++)
            {
               double A = a + x;
                double B = b + y;
                listt.Add(new FamilyInstanceCreationData(new XYZ(A, B, zz), fas, StructuralType.NonStructural));//把坐标放到集合里
                a = A;
                b = B;
            }
            doc.Create.NewFamilyInstances2(listt);//创建支吊架
            ts.Commit();
            return Result.Succeeded;
        }
    }
}