arx修改字体样式表的问题？求解决

sn13

我想修改字体样式表中的宽度因子，修改为0.8，怎么修改都不成功，求解决方法，附上代码如下：
AcDbTextStyleTable *pTextStyleTbl;
acdbHostApplicationServices()->workingDatabase()->getSymbolTable(pTextStyleTbl,AcDb::kForWrite);
AcDbTextStyleTableRecord *pTextStyleTblRcd=new  AcDbTextStyleTableRecord;
pTextStyleTbl->getAt(ACDB_MODEL_SPACE,pTextStyleTblRcd,AcDb::kForWrite);
pTextStyleTblRcd->setFont(L"宋体",0,0,134,49);
pTextStyleTblRcd->setXScale(0.8);

AcDbObjectId fontId;
pTextStyleTbl->add(fontId,pTextStyleTblRcd);
pTextStyleTblRcd->close();
pTextStyleTbl->close();
acdbHostApplicationServices()->workingDatabase()->setTextstyle(fontId);