尺寸标注：转角标注、对齐标注、角度标注、半径标注、直径标注和坐标标注。

需要头文件#include " dbdim.h "

（1）对齐标注：AcDbAlignedDimension类

构造函数定义为：

AcDbAlignedDimension( const AcGePoint3d& xLine1Point, const AcGePoint3d& xLine2Point, const AcGePoint3d& dimLinePoint, const ACHAR * dimText = NULL, AcDbObjectId dimStyle = AcDbObjectId::kNull);

第一个参数：xLine1Point：第一条尺寸边界线的起点；第二个参数：xLine2Point：第二条尺寸边界线的起点：第三个参数：dimLinePoint：通过尺寸线的一点；第四个参数：dimText ：标注文字；第五个参数：dimStyle ：样式。

AcDbObjectId CCreateEnt::CreateDimAligned(const AcGePoint3d& pt1,const AcGePoint3d& pt2, const AcGePoint3d& ptLine,const AcGeVector3d& vecOffset,const char* dimText)
{
AcDbAlignedDimension *pDim = new AcDbAlignedDimension(pt1, pt2,ptLine, dimText,AcDbObjectId::kNull);
AcDbObjectId dimensionId = CCreateEnt::PostToModelSpace(pDim);// 打开已经创建的标注，对文字的位置进行修改
AcDbEntity *pEnt = NULL;
Acad::ErrorStatus es = acdbOpenAcDbEntity(pEnt, dimensionId, AcDb::kForWrite);AcDbAlignedDimension *pDimension = AcDbAlignedDimension::cast(pEnt);
if (pDimension != NULL)
{
// 移动文字位置前，设置文字和尺寸线移动时的关系（这里指定为：尺寸线不动，在文字和尺寸线之间加箭头）
pDimension->setDimtmove(1);// 根据偏移向量修正文字插入点的位置
AcGePoint3d ptText = pDimension->textPosition();
ptText = ptText + vecOffset;
pDimension->setTextPosition(ptText);//尺寸文本的移动
}
pEnt->close();
return dimensionId;
}

注：移动标注文字必须在将其添加到模型空间之后进行。

（2）转角标注：AcDbRotatedDimension类

构造函数定义为：

AcDbRotatedDimension(double rotation, const AcGePoint3d& xLine1Point, const AcGePoint3d& xLine2Point, const AcGePoint3d& dimLinePoint, const ACHAR * dimText = NULL, AcDbObjectId dimStyle = AcDbObjectId::kNull);

第一个参数：rotation：标注的旋转角度；第二个参数：xLine1Point：第一条尺寸边界线的起点；第三个参数：xLine2Point：第二条尺寸边界线的起点；第四个参数：dimLinePoint：通过尺寸线的一点；第五个参数：dimText ：标注文字； 第五个参数：dimStyle ： 样式。

AcDbObjectId CCreateEnt::CreateDimRotated(const AcGePoint3d& pt1,const AcGePoint3d& pt2, const AcGePoint3d& ptLine,double rotation, const char* dimText,AcDbObjectId dimStyle)
{
AcDbRotatedDimension *pDim = new AcDbRotatedDimension(rotation,pt1, pt2, ptLine, dimText, dimStyle);
return CCreateEnt::PostToModelSpace(pDim);
}

（3）半径标注：AcDbRadialDimension类

构造函数定义为：

AcDbRadialDimension( const AcGePoint3d& center, const AcGePoint3d& chordPoint,double leaderLength, const ACHAR *  dimText = NULL,AcDbObjectId dimStyle = AcDbObjectId::kNull);

第一个参数：center：标注曲线的中心点；第二个参数：chordPoint：引线附着的坐标；第三个参数：leaderLength：引线长度；第四个参数：dimText ：标注文字； 第五个参数：dimStyle ： 样式。

//根据相对极坐标来确定一个点
AcGePoint3d CCalculation::PolarPoint(const AcGePoint3d& pt, double angle,double distance)
{
ads_point ptForm, ptTo;
ptForm[X] = pt.x;
ptForm[Y] = pt.y;
ptForm[Z] = pt.z;acutPolar(ptForm, angle, distance, ptTo);
return asPnt3d(ptTo);
}AcDbObjectId CCreateEnt::CreateDimRadial(const AcGePoint3d& ptCenter,double radius, double angle, double leaderLength)
{
AcGePoint3d ptChord = CCalculation::PolarPoint(ptCenter, angle,radius);
return CCreateEnt::CreateDimRadial(ptCenter, ptChord,leaderLength);
}

（4）直径标注：AcDbDiametricDimension类

构造函数定义为：

 AcDbDiametricDimension(const AcGePoint3d& chordPoint,const AcGePoint3d& farChordPoint,double leaderLength, const ACHAR * dimText = NULL, AcDbObjectId  dimStyle = AcDbObjectId::kNull);

第一个参数：chordPoint：第二个参数：farChordPoint：标注直径的两个端点；第三个参数：leaderLength：引线长度； 第四个参数：dimText ：标注文字； 第五个参数：dimStyle ： 样式。

AcDbObjectId CCreateEnt::CreateDimDiametric(const AcGePoint3d& ptCenter,double radius, double angle, double leaderLength)
{
// 计算标注通过点的位置
AcGePoint3d ptChord1, ptChord2;
ptChord1 = CCalculation::PolarPoint(ptCenter, angle, radius);
ptChord2 = CCalculation::PolarPoint(ptCenter,angle + CCalculation::PI(), radius);
return CCreateEnt::CreateDimDiametric(ptChord1, ptChord2,leaderLength);
}

（5）角度标注：AcDb2LineAngularDimension 类 AcDb3PointAngularDimension类

构造函数定义为：

AcDb2LineAngularDimension( const AcGePoint3d& xLine1Start,const AcGePoint3d& xLine1End,const AcGePoint3d& xLine2Start,const AcGePoint3d& xLine2End, const AcGePoint3d& arcPoint, const ACHAR * dimText = NULL,AcDbObjectId dimStyle = AcDbObjectId::kNull);

第一个参数：xLine1Start：第一条尺寸边界线的起点；第二个参数：xLine1End：第一条尺寸边界线的终点：第三个参数：xLine2Start：第二条尺寸边界线的起点；第四个参数：xLine2End：第二条尺寸边界线的终点；第五个参数：arcPoint：圆弧点；第六个参数：dimText ：标注文字； 第七个参数：dimStyle ： 样式。

 AcDb3PointAngularDimension(const AcGePoint3d& centerPoint, const AcGePoint3d& xLine1Point, const AcGePoint3d& xLine2Point, const AcGePoint3d& arcPoint, const ACHAR *dimText = NULL,AcDbObjectId dimStyle = AcDbObjectId::kNull);

第一个参数：centerPoint：中心点；第二个参数：xLine1Point：第一条尺寸边界线的起点；第三个参数：xLine2Point：第二条尺寸边界线的起点；第四个参数：arcPoint：圆弧点；第五个参数：dimText ：标注文字； 第六个参数：dimStyle ： 样式。

AcDbObjectId CCreateEnt::CreateDim2LineAngular(const AcGePoint3d& ptStart1,const AcGePoint3d& ptEnd1, const AcGePoint3d& ptStart2,const AcGePoint3d& ptEnd2, const AcGePoint3d& ptArc,const char* dimText, AcDbObjectId dimStyle)
{
AcDb2LineAngularDimension *pDim = new AcDb2LineAngularDimension(ptStart1, ptEnd1, ptStart2, ptEnd2, ptArc, dimText, dimStyle);
return CCreateEnt::PostToModelSpace(pDim);
}AcDbObjectId CCreateEnt::CreateDim3PtAngular(const AcGePoint3d& ptCenter,const AcGePoint3d& ptEnd1, const AcGePoint3d& ptEnd2,const AcGePoint3d& ptArc, const char* dimText,
AcDbObjectId dimStyle)
{
AcDb3PointAngularDimension *pDim = new AcDb3PointAngularDimension(ptCenter, ptEnd1, ptEnd2, ptArc, dimText, dimStyle);
return CCreateEnt::PostToModelSpace(pDim);
}

（6）坐标标注：AcDbOrdinateDimension类

AcDbOrdinateDimension(Adesk::Boolean useXAxis, const AcGePoint3d& definingPoint, const AcGePoint3d& leaderEndPoint,const ACHAR * dimText = NULL,AcDbObjectId  dimStyle  = AcDbObjectId::kNull);

第一个参数：useXAxis：是否是 X 轴标注；第二个参数：definingPoint：标注箭头的起始位置；第三个参数：leaderEndPoint：标注箭头的终止位置； 第四个参数：dimText ：标注文字； 第五个参数：dimStyle ： 样式。

AcDbObjectIdArray CCreateEnt::CreateDimOrdinate(const AcGePoint3d& ptDef,const AcGePoint3d& ptTextX, const AcGePoint3d& ptTextY)
{
AcDbObjectId dimId  = CCreateEnt::CreateDimOrdinate(Adesk::kTrue, ptDef,ptTextX);
AcDbObjectIdArray dimIds;
dimIds.append(dimId);
dimId = CCreateEnt::CreateDimOrdinate(Adesk::kFalse, ptDef,ptTextY);
dimIds.append(dimId);
return dimIds;
}AcDbObjectIdArray CCreateEnt::CreateDimOrdinate(const AcGePoint3d& ptDef,const AcGeVector3d& vecOffsetX, const AcGeVector3d&vecOffsetY)
{
AcGePoint3d ptTextX = ptDef + vecOffsetX;
AcGePoint3d ptTextY = ptDef + vecOffsetY;
return CCreateEnt::CreateDimOrdinate(ptDef, ptTextX, ptTextY);
}

看一下整体调用：

//根据相对直角坐标来计算一个点的位置：
AcGePoint3d CCalculation::RelativePoint(const AcGePoint3d& pt,double x, double y)
{
AcGePoint3d ptReturn(pt.x + x, pt.y + y, pt.z);
return ptReturn;
}void ZffCHAP2AddDimension()
{
// 指定起始点位置
AcGePoint3d pt1(200, 160, 0);
AcGePoint3d pt2= CCalculation::RelativePoint(pt1, -40, 0);
AcGePoint3d pt3 = CCalculation::PolarPoint(pt2,7 * CCalculation::PI() / 6, 20);
AcGePoint3d pt4 = CCalculation::RelativePoint(pt3, 6, -10);
AcGePoint3d pt5 = CCalculation::RelativePoint(pt1, 0, -20);// 绘制外轮廓线
CCreateEnt::CreateLine(pt1, pt2);
CCreateEnt::CreateLine(pt2, pt3);
CCreateEnt::CreateLine(pt3, pt4);
CCreateEnt::CreateLine(pt4, pt5);
CCreateEnt::CreateLine(pt5, pt1);// 绘制圆形
AcGePoint3d ptCenter1, ptCenter2;
ptCenter1 = CCalculation::RelativePoint(pt3, 16, 0);
ptCenter2 = CCalculation::RelativePoint(ptCenter1, 25, 0);
CCreateEnt::CreateCircle(ptCenter1, 3);
CCreateEnt::CreateCircle(ptCenter2, 4);AcGePoint3d ptTemp1, ptTemp2;// 转角标注：水平标注
ptTemp1 = CCalculation::RelativePoint(pt1, -20, 3);
CCreateEnt::CreateDimRotated(pt1, pt2, ptTemp1, 0);// 转角标注：垂直标注
ptTemp1 = CCalculation::RelativePoint(pt1, 4, 10);
CCreateEnt::CreateDimRotated(pt1, pt5, ptTemp1,CCalculation::PI() / 2);// 转角标注
ptTemp1 = CCalculation::RelativePoint(pt3, -3, -6);
CCreateEnt::CreateDimRotated(pt3, pt4, ptTemp1,7 * CCalculation::PI() / 4);// 对齐标注
ptTemp1 = CCalculation::RelativePoint(pt2, -3, 4);
CCreateEnt::CreateDimAligned(pt2, pt3, ptTemp1,AcGeVector3d(4, 10, 0), "new position");// 角度标注
ptTemp1 = CCalculation::RelativePoint(pt5, -5, 5);
CCreateEnt::CreateDim3PtAngular(pt5, pt1, pt4, ptTemp1);// 半径标注
ptTemp1 = CCalculation::PolarPoint(ptCenter1,CCalculation::PI() / 4, 3);
CCreateEnt::CreateDimRadial(ptCenter1, ptTemp1, -3);// 直径标注
ptTemp1 = CCalculation::PolarPoint(ptCenter2,CCalculation::PI() / 4, 4);
ptTemp2 = CCalculation::PolarPoint(ptCenter2,CCalculation::PI() / 4, -4);
CCreateEnt::CreateDimDiametric(ptTemp1, ptTemp2, 0);// 坐标标注
CCreateEnt::CreateDimOrdinate(ptCenter2, AcGeVector3d(0, -10, 0),AcGeVector3d(10, 0, 0));
}

AcDbDimension::setDimensionText（）：设置尺寸文本的内容。