如何直接生成"LWPOLYLINE"？[求助]

lhb.nj

如何直接生成"LWPOLYLINE"？

zhangsan

void
createPolyline()
{
    // Set four vertex locations for the pline.
    //
    AcGePoint3dArray ptArr;
    ptArr.setLogicalLength(4);
    for (int i = 0; i < 4; i++) {
        ptArr.set((double)(i/2), (double)(i%2), 0.0);
    }

    // Dynamically allocate an AcDb2dPolyline object,
    // given four vertex elements whose locations are supplied
    // in ptArr.  The polyline has no elevation, and is
    // explicitly set as closed.  The polyline is simple;
    // that is, not curve fit or a spline.  By default, the
    // widths are all 0.0 and there are no bulge factors.
    //
    AcDb2dPolyline *pNewPline = new AcDb2dPolyline(
        AcDb::k2dSimplePoly, ptArr, 0.0, Adesk::kTrue);
    pNewPline->setColorIndex(3);

    // Get a pointer to a Block Table object.
    //
    AcDbBlockTable *pBlockTable;
    acdbHostApplicationServices()->workingDatabase()
        ->getSymbolTable(pBlockTable, AcDb::kForRead);

    // Get a pointer to the MODEL_SPACE BlockTableRecord.
    //
    AcDbBlockTableRecord *pBlockTableRecord;
    pBlockTable->getAt(ACDB_MODEL_SPACE, pBlockTableRecord,
        AcDb::kForWrite);
    pBlockTable->close();

    // Append the pline object to the database and
    // obtain its object ID.
    //
    AcDbObjectId plineObjId;
    pBlockTableRecord->appendAcDbEntity(plineObjId,
        pNewPline);
    pBlockTableRecord->close();

    // Make the pline object reside on layer "0".
    //
    pNewPline->setLayer("0");
    pNewPline->close();
}

lhb.nj

createPolyline()生成的是 "OLYLINE"而非"LWPOLYLINE"
其DXF组码是：
(  -1.  <Entity name: [40072D58][437B6947]>)
(   0.  <string: POLYLINE>)
(   5.  <string: 2B>)
( 100.  <string: AcDbEntity>)
(  67.  <short: 0>)
(   8.  <string: 0>)
(  62.  <short: 3>)
( 100.  <string: AcDb2dPolyline>)
(  66.  <short: 1>)
(  10.  <3dpoint:     0.0000,    0.0000,    0.0000>)
(  70.  <short: 1>)
(  40.  <real:    0.000000000000000>)
(  41.  <real:    0.000000000000000>)
( 210.  <3dpoint:     0.0000,    0.0000,    1.0000>)
(  71.  <short: 0>)
(  72.  <short: 0>)
(  73.  <short: 0>)
(  74.  <short: 0>)
(  75.  <short: 0>)
而不是：
(  -1.  <Entity name: [40072DC0][437B69DF]>)
(   0.  <string: LWPOLYLINE>)
(   5.  <string: 38>)
( 100.  <string: AcDbEntity>)
(  67.  <short: 0>)
(   8.  <string: 0>)
( 100.  <string: AcDbPolyline>)
(  90.  <long: 4>)
(  70.  <short: 1>)
(  43.  <real:    0.000000000000000>)
(  38.  <real:    0.000000000000000>)
(  39.  <real:    0.000000000000000>)
(  10.  <3dpoint:    -0.5210,   -0.0031,    0.0000>)
(  40.  <real:    0.000000000000000>)
(  41.  <real:    0.000000000000000>)
(  42.  <real:    0.000000000000000>)
(  10.  <3dpoint:    -0.5210,    0.9969,    0.0000>)
(  40.  <real:    0.000000000000000>)
(  41.  <real:    0.000000000000000>)
(  42.  <real:    0.000000000000000>)
(  10.  <3dpoint:     0.4790,   -0.0031,    0.0000>)
(  40.  <real:    0.000000000000000>)
(  41.  <real:    0.000000000000000>)
(  42.  <real:    0.000000000000000>)
(  10.  <3dpoint:     0.4790,    0.9969,    0.0000>)
(  40.  <real:    0.000000000000000>)
(  41.  <real:    0.000000000000000>)
(  42.  <real:    0.000000000000000>)
( 210.  <3dpoint:     0.0000,    0.0000,    1.0000>)

zhangsan

它影响pline的输出，大概也影响。。。

lhb.nj

系统变量PLINETYPE=1,2只影响PLINE命令，而不能影响直接生成实体！
而命令CONVERT可以转换2DPOLYLINE为LWPOLYLINE！不知它是如何做的？

hothua

首先我要说明的是LWPOLYLINE是Lisp语言的DXF慨念，在ARX中就是AcDbPolyline，而LISP中的POLYLINE是3D线，好久没写这些东西了，有的地方我也忘了。县列出ARX程序和LISP程序如下：
／／ptArray，坐标点集
bool makePolyline(AcGePoint3dArray &ptArray)
{
        unsigned int ptNum;
        ptNum=ptArray.length();
        if(ptNum>2)
        {       
        AcDbPolyline *newEnt;
        newEnt=new AcDbPolyline(ptNum);
        for(unsigned int num=0;num<ptNum;++num)
        {
                AcGePoint2d pt;
                pt[0]=ptArray[num][0];
                pt[1]=ptArray[num][1];
                if(newEnt->addVertexAt(num,pt,0.0)!=Acad::eOk)
                {
                        newEnt->close();
                        return false;
                }
        }
        if(appendToPaperOrModelSpace((AcDbEntity *)newEnt,0)!= Acad::eOk)
        {
                newEnt->close();
                return false;
        }       
        newEnt->close();
        return true;
}

Acad::ErrorStatus appendToPaperOrModelSpace (AcDbEntity* parEntity, Adesk::Boolean parbToPaperSpace)
{
       
        Acad::ErrorStatus        ErrorStatus;
        AcDbDatabase*                        pDataBase;
        AcDbBlockTable*                        pBlockTable;
        AcDbBlockTableRecord*        pBlockTableRecord;

       
    pDataBase        = acdbCurDwg();
       
        if (pDataBase == NULL)                
                        return Acad::eNoDatabase;
        ErrorStatus = pDataBase->getBlockTable(pBlockTable, AcDb::kForRead);       
        if (ErrorStatus != Acad::eOk)        
                        return ErrorStatus;
        if (parbToPaperSpace)       
                ErrorStatus = pBlockTable->getAt(ACDB_PAPER_SPACE, pBlockTableRecord, AcDb::kForWrite);
        else       
                ErrorStatus = pBlockTable->getAt(ACDB_MODEL_SPACE, pBlockTableRecord, AcDb::kForWrite);               
        if (ErrorStatus != Acad::eOk)
        {
                pBlockTable->close();
                return ErrorStatus;
        }       
        ErrorStatus = pBlockTableRecord->appendAcDbEntity (parEntity);
    pBlockTableRecord->close();
    pBlockTable->close();
        return ErrorStatus;
}       
；LISP 具体参数就不用我说了吧
(defun make_pl(points layer ltype color wid code / n flag m_elist ele xy_l kk xy)
  (setq n (length points))
  (if (>= n 2)
    (if (equal (nth 0 points) (nth (1- n) points) 0.001)
      (setq flag '(70 . 1) n (1- n) kk 1)
      (setq flag '(70 . 0) kk 0)
    )
  )
  (if (not layer)
    (setq layer (getvar "clayer"))
  )
  (if (not wid)
    (setq wid (getvar "plinewid"))
  )
  (if (not code)
    (setq code (getvar "thickness"))
  )
  (if (>= n 2)
    (progn
      (entmake)
      (if (nth 2 (car points))
        (setq ele (nth 2 (car points)))
        (setq ele 0)
      )
      (setq m_elist (list '(0 . "LWPOLYLINE") '(100 . "AcDbEntity") (cons 8 layer)))
      (if (and color (/= color "BYLAYER") (/= color 256))
      (setq m_elist (append m_elist (list (cons 62 color))))
      )
      (if (and ltype (/= ltype "BYLAYER"))
      (setq m_elist (append m_elist (list (cons 6 ltype))))
      )
      (setq m_elist (append m_elist (list '(100 . "AcDbPolyline")) (list (cons 90 n))
                            (list flag) (list (cons 38 ele))
                    )
            xy_l '()        
      )
      (setq m_elist (append m_elist (list (cons 39 code))))
      (repeat n
        (setq xy (nth kk points)
              xy (list (car xy) (cadr xy))
              xy_l (append xy_l (list (list 10 (car xy) (cadr xy)) (cons 40 wid) (cons 41 wid) '(42 . 0.0)))
              kk (1+ kk)
        )
      )
      (setq m_elist (append m_elist xy_l (list '(210 0.0 0.0 1.0))))   
      (entmake m_elist)
    )
  )
)