新建一个COM组件对象
[id(251), helpstring("NewEntity")] IDispatch* NewEntity(BSTR pszClassName);
例如: 现在支持的类名
IMxDrawLine,IMxDrawPolyline,IMxDrawArc,IMxDrawCircle,IMxDrawXline,IMxDrawComment,IMxDrawRay,IMxDrawQrCode IMxDrawText,IMxDrawMText,IMxDrawPointEntity,IMxDrawRasterImage,IMxDrawSpline,IMxDrawDimAligned,IMxDrawDimRadial,IMxDrawImageMark
_DMxDrawX 方法