[ARX程序]：怎么画AcDbMLine实体？

hanahana

给个最简单的例子，谢谢

XDSoft

给你贴个ADN资料：

How to create an Mline using ObjectARX?  
ID    45184  
Applies to:    AutoCAD 2000

Date    6/22/2000  

This document is part of    Symbol Tables   Named Objects Dictionary   MLines     


Question
How do I create an MLINE entity in AutoCAD using ObjectARX? When I try this, an
MLINE is not created and an error message does not occur indicating this was
unsuccessful.
Answer
The most likely cause for this is that you did not set the MLINE style to the
MLINE entity as it was created.

If an MLINE style is not set, AutoCAD does not know how to visually represent
the MLINE despite the fact that the MLine entity is valid and is appended to the
DWG database.

The following code creates an MLINE using the "Standard" MLINE style that is
always present in any DWG database.

NOTE: You can also create another MLINE style using the AcDbMlineStyle ARX
class.
AcDbMline *l =new AcDbMline ;
l->setNormal (AcGeVector3d (0, 0, 1)) ;
l->setScale (1.5) ;

AcDbDictionary *d ;
acdbHostApplicationServices ()->workingDatabase ()
->getNamedObjectsDictionary (d, AcDb::kForRead) ;
AcDbDictionary *ls ;
d->getAt ("ACAD_MLINESTYLE", (AcDbObject*&)ls, AcDb::kForRead) ;
d->close () ;
AcDbObjectId id ;
ls->getAt ("Standard", id) ;
ls->close () ;

l->setStyle (id) ;

l->appendSeg (AcGePoint3d (0, 0, 0)) ;
l->appendSeg (AcGePoint3d (10, 0, 0)) ;
l->appendSeg (AcGePoint3d (10, 10, 0)) ;
l->appendSeg (AcGePoint3d (20, 20, 0)) ;
l->appendSeg (AcGePoint3d (20, 100, 0)) ;

// Now, the AcDbMline entity is ready to be appended to the DWG database