C#CAD二次开发什么定入一条Xline

在C#中，您可以使用AcadDatabaseUtility.GetActiveDocument方法获取当前活动文档，然后使用Document.EditorUserInterface.StartUserInteraction方法启动用户交互会话，以允许用户指定Xline的起点和方向。最后，使用Transaction类来创建Xline对象并将其添加到当前空间。

以下是一个示例代码，演示如何在AutoCAD中创建Xline：

using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Geometry;
using Autodesk.AutoCAD.Runtime;

namespace MyCommands
{
    public class MyCommandsClass
    {
        [CommandMethod("CreateXline")]
        public void CreateXline()
        {
            Document doc = Application.DocumentManager.MdiActiveDocument;
            Editor ed = doc.Editor;

            // Prompt user for Xline start and direction
            PromptPointOptions ppo = new PromptPointOptions("\nSpecify start point of Xline: ");
            PromptPointResult ppr = ed.GetPoint(ppo);
            if (ppr.Status != PromptStatus.OK)
                return;

            Point3d startPoint = ppr.Value;

            ppo = new PromptPointOptions("\nSpecify direction of Xline: ");
            ppo.UseBasePoint = true;
            ppo.BasePoint = startPoint;
            ppo.UseDashedLine = true;
            ppr = ed.GetPoint(ppo);
            if (ppr.Status != PromptStatus.OK)
                return;

            Vector3d direction = ppr.Value - startPoint;

            // Create Xline
            using (Transaction tr = doc.TransactionManager.StartTransaction())
            {
                BlockTableRecord btr = (BlockTableRecord)tr.GetObject(SymbolUtilityServices.GetBlockModelSpaceId(doc.Database), OpenMode.ForWrite);

                Xline xline = new Xline(startPoint, direction.GetNormal());
                btr.AppendEntity(xline);
                tr.AddNewlyCreatedDBObject(xline, true);

                tr.Commit();
            }

            ed.Regen();
        }
    }
}

您可以将此代码保存为命令程序集，然后在AutoCAD中使用CreateXline命令创建Xline。