绘制多边形并计算其面积的一个demo

绘制多边形并计算其面积的一个demo

 

int drawPolyline(){Acad::ErrorStatus es = Acad::eOk;AcGePoint3dArray vertexArray;int iErrSta = 0, i = 0;while (1){//由于是多边形,即最终要封闭,所以就不需要提示用户来封闭它,如果//多边形变成了多义线,只需要这个判断,即加入acedInitGet,即关键字进行判断AcGePoint3d tempPt = AcGePoint3d::kOrigin;if ( 0 == i)iErrSta = acedGetPoint(NULL, _T("/n指定下一点:"), asDblArray(tempPt));elseiErrSta = acedGetPoint(asDblArray(vertexArray.at(i-1)),_T("/n指定下一点:"), asDblArray(tempPt));if (RTNORM == iErrSta)vertexArray.append(tempPt);elsebreak;if (i>0){//模拟橡皮筋效果,如果生成数组直线或者圆弧,加入到模型,最后删除效果更好acedGrDraw(asDblArray(vertexArray.at(i-1)),asDblArray(tempPt),256,0);}i ++;}if (vertexArray.length() < 2)return 1;//加入到模型空间中AcDbBlockTable* pTable = NULL;if (Acad::eOk != acdbHostApplicationServices() ->workingDatabase()->getBlockTable(pTable, AcDb::kForRead))return 2;AcDbBlockTableRecord* pBlockTableReocrd;if (Acad::eOk != pTable ->getAt(ACDB_MODEL_SPACE, pBlockTableReocrd, AcDb::kForWrite)){pTable ->close();return 3;}pTable ->close();AcDbPolyline* pPolyline = new AcDbPolyline(vertexArray.length());for (int i = 0; i < vertexArray.length(); i ++){pPolyline ->addVertexAt(i, vertexArray[i].convert2d(AcGePlane::kXYPlane));}pPolyline ->setClosed(Adesk::kTrue);AcDbObjectId polylineId;pBlockTableReocrd ->appendAcDbEntity(polylineId, pPolyline);//获取多边形的面积double dArea = 0.0;pPolyline ->getArea(dArea);pPolyline ->close();pBlockTableReocrd ->close();acutPrintf("/n多边形的面积为:%lf",dArea);return 0;}