创建 Polyline 对象

创建 Polyline 对象 本实例是在模型空间里创建一条包含两段的多段线对象(包含三个点)  添加AutoCAD的命名空间using Autodesk.AutoCAD.Runtime;using Autodesk.AutoCAD.ApplicationServices;using Autodesk.AutoCAD.DatabaseServices;using Autode