ObjectARX之Mac os开发

网上关于ObjectARX开发的相关介绍都基于Windows环境。Mac 环境的开发几乎没有，下面介绍Mac环境下ObjectARX的开发。

 AutoCAD ObjectARX开发必备条件:

1. 安装Mac 版AutoCAD

2. 安装AutoCAD版本对应的ObjectARX 的SDK

本文以AutoCAD 2018 及对应的ObjectARX SDK，ObjectARX 2018 SDK 下载链接:http://help.autodesk.com/view/OARXMAC/2018/ENU/

ObjectARX SDK安装成功后的路径如下图:

打开Xcode 新建项目时会出现Auto CAD项目信息:

新建arx项目后，xcode会自动创建一个arxmian.cpp文件。代码如下

#if defined(_DEBUG) && !defined(AC_FULL_DEBUG)
#error _DEBUG should not be defined except in internal Adesk debug builds
#endif

#include <aced.h>
#include <rxregsvc.h>

void mycmd()
{
    acutPrintf(L"My command");
}

// Initialization function called from acrxEntryPoint during
// kInitAppMsg case.  This function is used to add commands
// to the command stack.
//
void
initApp()
{
    acedRegCmds->addCommand(L"MYARX_COMMANDS", L"mycmd", L"mycmd", ACRX_CMD_MODAL, mycmd);
}


// Clean up function called from acrxEntryPoint during the
// kUnloadAppMsg case.  This function removes this app's
// command set from the command stack.
//
void
unloadApp()
{
    acedRegCmds->removeGroup(L"MYARX_COMMANDS");
}


// ARX entry point
//
extern "C"
AcRx::AppRetCode acrxEntryPoint(AcRx::AppMsgCode msg, void* appId)
{
    switch (msg) {
    case AcRx::kInitAppMsg:
        acrxDynamicLinker->unlockApplication(appId);
    acrxDynamicLinker->registerAppMDIAware(appId);
        initApp();
        break;
    case AcRx::kUnloadAppMsg:
        unloadApp();
        break;
    default: break;
    }
    return AcRx::kRetOK;
}

例子会注册一个新的命令到AutoCAD中，下面我们通过命令插入一条直线

void createLine() {
    AcGePoint3d startPoint(4, 2, 0);
    AcGePoint3d endPoint(6, 5, 0);
    AcDbLine* pLine = new AcDbLine(startPoint, endPoint);
    //获取block 表
    AcDbBlockTable *pBlockTable;
    acdbHostApplicationServices()->workingDatabase()->getBlockTable(pBlockTable, AcDb::kForRead);
    //获取模型空间
    AcDbBlockTableRecord* pModelSpace;
    pBlockTable->getAt(ACDB_MODEL_SPACE, pModelSpace, AcDb::kForWrite);
    //向模型空间添加该直线并返回其id
    AcDbObjectId lineId;
    pModelSpace->appendAcDbEntity(lineId, pLine);
    
    //关闭相关对象
    pLine->close();
    pModelSpace->close();
    pBlockTable->close();
}

然后在mycmd函数中调用该函数:

void createLine();

void mycmd()
{
    acutPrintf(L"Create Line");
    createLine();
}

编译项目生成bundle文件

然后我们打开AutoCAD 2018 加载该bundle文件:

在AutoCAD的命令行中输入 mycmd就会绘制一条线出来