如何獲得CAD視的左下角和右上角的坐標(ObjectARX)

妳解決了嗎，我在網上收到這個了，妳設這樣解決的嗎？

AcGePoint3d ptMax = acdbHostApplicationServices()->workingDatabase()->extmax(); //右上角點

AcGePoint3d ptMin = acdbHostApplicationServices()->workingDatabase()->extmin(); //左下角點