UCSTools.cs

using System;
using System.Runtime.InteropServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Geometry;

namespace DotNetARX
{
    /// <summary>
    /// UCS操作类
    /// </summary>
    public static class UCSTools
    {
        [DllImport("acad.exe", CallingConvention = CallingConvention.Cdecl, EntryPoint = "acedTrans")]
        private static extern int acedTrans(double[] point, IntPtr fromResbuf, IntPtr toResbuf, int displacement, double[] result);
        /// <summary>
        /// 坐标系的类型
        /// </summary>
        public enum CoordSystem
        {
            /// <summary>
            /// WCS
            /// </summary>
            WCS = 0,
            /// <summary>
            /// UCS
            /// </summary>
            UCS,
            /// <summary>
            /// DCS
            /// </summary>
            DCS,
            /// <summary>
            /// PSDCS
            /// </summary>
            PSDCS
        }

        /// <summary>
        /// 将点或矢量从一个坐标系转换到另一个坐标系
        /// </summary>
        /// <param name="pt">坐标，表示点或位移矢量</param>
        /// <param name="from">源坐标系</param>
        /// <param name="to">目标坐标系</param>
        /// <param name="disp">位移矢量标记，1表示位移矢量，0表示点</param>
        /// <returns>返回转化后的坐标</returns>
        public static Point3d TranslateCoordinates(this Point3d pt, CoordSystem from, CoordSystem to, int disp)
        {
            double[] result=new double[3];
            acedTrans(pt.ToArray(),
                new ResultBuffer(new TypedValue(5003, from)).UnmanagedObject,
                new ResultBuffer(new TypedValue(5003, to)).UnmanagedObject,
                disp, result);
            return new Point3d(result);
        }

        /// <summary>
        /// 将点从一个坐标系转换到另一个坐标系
        /// </summary>
        /// <param name="pt">点</param>
        /// <param name="from">源坐标系</param>
        /// <param name="to">目标坐标系</param>
        /// <returns>返回转化后的坐标</returns>
        public static Point3d TranslateCoordinates(this Point3d pt, CoordSystem from, CoordSystem to)
        {
            return pt.TranslateCoordinates(from, to, 0);
        }
 
        /// <summary>
        /// 创建一个新的UCS
        /// </summary>
        /// <param name="db">数据库对象</param>
        /// <param name="UCSName">要创建的UCS名称</param>
        /// <returns>返回创建的UCS的Id</returns>
        public static ObjectId AddUCS(this Database db, string UCSName)
        {
            var trans=db.TransactionManager;
            //打开UCS表
            UcsTable ut=(UcsTable)trans.GetObject(db.UcsTableId, OpenMode.ForRead);
            if (!ut.Has(UCSName))//如果不存在名为UCSName的UCS，则新建一个UCS
            {
                //定义一个新的UCS
                UcsTableRecord utr=new UcsTableRecord();
                utr.Name = UCSName;//设置UCS名
                ut.UpgradeOpen();//切换UCS表的状态为写以添加新的UCS
                //将UCS的信息添加到UCS表中
                ut.Add(utr);
                //把UCS添加到事务处理中
                trans.AddNewlyCreatedDBObject(utr, true);
                ut.DowngradeOpen();//为了安全，将UCS表的状态切换为读
            }
            return ut[UCSName];//返回新添加的UCS的ObjectId
        }

        /// <summary>
        /// 将UCS表中已经存在的一个UCS设置为当前UCS
        /// </summary>
        /// <param name="db">数据库对象</param>
        /// <param name="UCSName">UCS名称</param>
        /// <returns>如果设置成功返回true，否则返回false</returns>
        public static bool SetCurrentUCS(this Database db, string UCSName)
        {
            var trans=db.TransactionManager;
            Editor ed=db.GetEditor();
            //打开UCS表
            UcsTable ut=(UcsTable)trans.GetObject(db.UcsTableId, OpenMode.ForRead);
            //如果不存在名为UCSName的UCS，则返回
            if (!ut.Has(UCSName)) return false;
            //打开当前活动的视口为写的状态
            ViewportTableRecord vtr=(ViewportTableRecord)trans.GetObject(db.CurrentViewportTableRecordId(), OpenMode.ForWrite);
            //设置当前UCS
            vtr.SetUcs(ut[UCSName]);
            vtr.DowngradeOpen();
            //更新视口
            ed.UpdateTiledViewportsFromDatabase();
            return true;
        }

        /// <summary>
        /// 获取当前UCS
        /// </summary>
        /// <param name="db">数据库对象</param>
        /// <returns>返回当前UCS的Id</returns>
        public static ObjectId GetCurrentUCS(this Database db)
        {
            var trans=db.TransactionManager;
            Editor ed=db.GetEditor();
            //打开UCS表
            UcsTable ut=(UcsTable)trans.GetObject(db.UcsTableId, OpenMode.ForRead);
            //打开当前活动的视口
            ViewportTableRecord vtr=(ViewportTableRecord)trans.GetObject(db.CurrentViewportTableRecordId(), OpenMode.ForRead);
            //返回当前UCS的ObjectId
            return vtr.UcsName;
        }

        /// <summary>
        /// 设置UCS的原点
        /// </summary>
        /// <param name="ucsId">UCS的Id</param>
        /// <param name="pt">要设置的UCS原点坐标</param>
        public static void SetUCSOrigin(this ObjectId ucsId, Point3d pt)
        {
            Database db=ucsId.Database;
            var trans=db.TransactionManager;
            //打开UCS
            UcsTableRecord utr=trans.GetObject(ucsId, OpenMode.ForRead) as UcsTableRecord;
            if (utr == null) return;//若UCS不存在，则返回
            utr.UpgradeOpen();//切换UCS为写的状态
            utr.Origin = pt;//设置UCS的原点
            utr.DowngradeOpen();//为了安全，切换UCS为读的状态
        }

        /// <summary>
        /// 旋转UCS
        /// </summary>
        /// <param name="ucsId">UCS的Id</param>
        /// <param name="rotateAngle">旋转角度</param>
        /// <param name="rotateAxis">旋转轴</param>
        public static void RotateUCS(this ObjectId ucsId, double rotateAngle, Vector3d rotateAxis)
        {
            Database db=ucsId.Database;
            var trans=db.TransactionManager;
            //打开UCS
            UcsTableRecord utr=trans.GetObject(ucsId, OpenMode.ForRead) as UcsTableRecord;
            if (utr == null) return;//若UCS不存在，则返回
            utr.UpgradeOpen();//切换UCS为写的状态
            Vector3d xAxis=utr.XAxis;//UCS的X轴方向
            Vector3d yAxis=utr.YAxis;//UCS的Y轴方向
            //旋转UCS
            utr.XAxis = xAxis.RotateBy(rotateAngle * Math.PI / 180, rotateAxis);
            utr.YAxis = yAxis.RotateBy(rotateAngle * Math.PI / 180, rotateAxis);
            utr.DowngradeOpen();//为了安全，切换UCS为读的状态
        }
    }
}