方法要求ref object参数, 如果传递double值？

            object zfactor=new object();
            zfactor = 1.0;
            IGeoDataset pGeodsResult = psurfaceOp.CutFill(pGeodsUp, pGeodsDown, ref zfactor);//CutFill分析

object对象直接赋值double数值即可