【ARX 一步一步开发CAD】03-画线

colinzhoucn

  l) s+ v  L9 w- }

这是比较简单的部分了，可以参考现有书籍。在网上下载两个画线的函数：

直线：

void LineCreate(AcGePoint3d ptStart,AcGePoint3d ptEnd)
5 p5 R5 I7 ]% K5 l' G{
AcDbLine * pLine = new AcDbLine( ptStart , ptEnd );
) \0 C6 `7 I: G; t( u6 i# p// 获得指向块表的指针
+ A1 l7 C: a7 F" p& x0 sAcDbBlockTable *pBlockTable; acdbHostApplicationServices()->workingDatabase()
->getBlockTable(pBlockTable, AcDb::kForRead);
* A: X) N, l9 ]5 V2 |8 z// 获得指向特定的块表记录（模型空间）的指针
( D+ H) g# t# y5 zAcDbBlockTableRecord *pBlockTableRecord;
, J; k4 R: E- `& r8 B5 {pBlockTable->getAt(ACDB_MODEL_SPACE, pBlockTableRecord, AcDb::kForWrite);
3 K: }6 h# z+ Q. @// 将AcDbLine类的对象添加到块表记录中
AcDbObjectId lineId;
% M3 B2 a  l( t" I0 ~pBlockTableRecord->appendAcDbEntity(lineId, pLine);
& G& Y( m' z; [0 i  _// 关闭图形数据库的各种对象
) x; n- U: Q- P- |# {* xpBlockTable->close();
pBlockTableRecord->close();
pLine->close();
}
) p& ~7 D( k( l多线段：
void CreatePolyline(AcGePoint2dArray points ,double width)
- `& X8 C# ^/ E& g2 ~  D{
, W" D. u" R* B- ?1 p1 Yint numVertices = points.length();
9 r2 I* g4 t' t! m" @' a% }9 tAcDbPolyline *pPoly = new AcDbPolyline(numVertices);
0 C9 [4 m7 J& ~! m7 J! m! y8 i: O2 bfor (int i = 0; i < numVertices; i++)
) [8 W2 ]$ b+ w# G! J% C4 v( A{
  m: b8 g: V* D# P  a0 _5 C; spPoly->addVertexAt(i, points.at(i), 0, width, width);
$ w+ o/ B% j6 W7 E/ O) X9 N}
AcDbObjectId polyId;
9 [4 R; {) {; G- n* RpolyId = PostToModelSpace(pPoly);
//        return polyId;
}
( k% p1 M6 Z/ z% A' \static AcDbObjectId PostToModelSpace(AcDbEntity* pEnt)
{
9 q2 M& @0 F  V9 zAcDbBlockTable *pBlockTable;
7 T' ^9 `+ u& Z) _. ^9 B  BacdbHostApplicationServices()->workingDatabase() ->getBlockTable(pBlockTable, AcDb::kForRead);
AcDbBlockTableRecord *pBlockTableRecord;
( ]. o. m6 g5 x" W& t4 tpBlockTable->getAt(ACDB_MODEL_SPACE, pBlockTableRecord, AcDb::kForWrite);
$ t, C3 \$ E8 I* DAcDbObjectId entId;
pBlockTableRecord->appendAcDbEntity(entId, pEnt);
# r- S, K/ `- F% U: k: V3 ?0 lpBlockTable->close();
pBlockTableRecord->close();
  M' G/ v( a! cpEnt->close();
6 n9 W; i2 {1 |return entId;

}
需要注意的是：创建线段与显示线段需要不同的代码。

参考：http://www.colinchou.com/archives/242

: j# h* b# d% r' R6 i

! D9 i8 ~- U, \- d; t3 S
% @0 \" _, L0 a' I
http://www.3dportal.cn/discuz/source/plugin/sina_xweibo_x3/xwb/images/bgimg/icon_logo.png 该贴已经同步到 colinzhoucn的微博