ObjectARX学习笔记

来源：互联网发布：支持ed2k下载软件编辑：程序博客网时间：2024/04/29 17:26

一、AutoCAD APIs支持：

1，ObjectARX
2，.NET Managed API
3，COM Automation (VB, Java, Delphi, etc.)
4，AutoLISP

二次开发编程主要采用ObjectARX)和RealDWG，其中ObjectARX是免费的，RealDWG是收费的。

（http://www.autodesk.com/objectarx,

http://usa.autodesk.com/adsk/servlet/index?siteID=123112&id=770257）

API架构：

二、ObjectARX

1，ObjectARX是什么？

AutoCAD Runtime eXtension

A DLL plug-in model
A set of Object Oriented C++ libraries
A framework

2，ObjectARX能做什么？
Modify and extend the drawing database
Create/modify/erase objects
Create new types of objects
Modify AutoCAD’s user interface
Commands
Toolbars/dialogs
Properties Window
Design Center
Display system
Monitor/Modify AutoCAD’s standard behavior
Event notifications
Input point acquisition
3，.ARX = .DLL + 2 exported functions

acrxEntryPoint
acrxGetApiVersion

三、ObjectARX架构

AcDbDatabase 结构体系

Block Table:

三个默认的记录：*MODEL_SPACE, *PAPER_SPACE, *PAPER_SPACE0
实体只有添加到上述三个记录中才能在AutoCAD中显示。

AcRxObject (在 rxobject.h 中定义)

cast down-cast pointer safely
isA get class descriptor
isKindOf is object derived from?
AcDbEntity *ent;if (ent->isKindOf( AcDbLine::desc())){    AcDbLine *line = AcDbLine::cast(ent);    //do something with line->startPoint()...}

四、AutoCAD图形数据库

m