AutoCAD.Net/C#.Net QQ群:193522571 当用户使用的不是默认的WCS坐标系时，打印程序容易打成空白，因为点没有转换

Point3d pt1 = Autodesk.AutoCAD.Internal.Utils.UcsToDisplay(item.MinPoint, false);
Point3d pt2 = Autodesk.AutoCAD.Internal.Utils.UcsToDisplay(item.MaxPoint, false);
Point2d pStart = Point3dToPoint2d(pt1);
Point2d pEnd = Point3dToPoint2d(pt2);
//设置打印范围
Extents2d exWin = new Extents2d(pStart, pEnd);