ArcEngine 实现 SurfaceAnalysis的Area/Volumn功能

        /// <summary>
        /// 从目录加载Tin
        /// Esri的TIN，是一个文件夹，下面包好8个名称固定的adf文件
        /// </summary>
        /// <param name="folder">TinDataSet的父目录</param>
        /// <param name="tinDataset">tinDataSet的名称</param>
        /// <returns></returns>
        public ITin GetTinLayer(string folder, string tinDataset)
        {
            IWorkspaceFactory pWSFact = new TinWorkspaceFactoryClass();
            IWorkspace pWS = pWSFact.OpenFromFile(folder, 0);
            ITinWorkspace pTinWS = pWS as ITinWorkspace;
            ITin pTin = pTinWS.OpenTin(tinDataset);
            return pTin;
        }

   li_TinDataset = new List<string> { "tdenv.adf", "tedg.adf", "thul.adf", "tmsk.adf", "tmsx.adf", "tnod.adf", "tnxy.adf", "tnz.adf" };  
 /// <summary>
        /// 检查是否是TIN dataset
        /// </summary>
        /// <param name="folderpath">用户选择的folder</param>
        /// <returns></returns>
        public bool CheckTinDataSet(string folderpath)
        {
            if (!Directory.Exists(folderpath)) return false;
            DirectoryInfo di = new DirectoryInfo(folderpath);
            FileInfo[] ar_fi= di.GetFiles("*.adf");
            List<string> li_tem=new List<string>();
            for (int i = 0; i <= ar_fi.Length - 1; i++)
            {
                li_tem.Add(ar_fi[i].Name); 
            }

            int afirmed = 0;            for (int i = 0; i <= li_TinDataset.Count - 1; i++)
            {
                if (li_tem.Contains(li_TinDataset[i])) afirmed++;
                else break;
            }

            if (afirmed == 8) return true;
            else return false;
        }

        /// <summary>
        /// 将整个TIN作为计算对象,使用此方法
        /// </summary>
        /// <param name="Tin">TinLayer</param>
        /// <param name="planeheight">参考面高度</param>
        public void CalculateAreaVolumeISurface(ITin Tin, double planeheight,esriPlaneReferenceType aboveOrBelow,out double projectedArea,out double surfaceArea,out double volume)
        {
            ISurface pSurface = Tin as ISurface;
            projectedArea = pSurface.GetProjectedArea(planeheight, aboveOrBelow);
            surfaceArea = pSurface.GetSurfaceArea(planeheight, aboveOrBelow);
            volume = pSurface.GetVolume(planeheight, aboveOrBelow);

            projectedArea = Math.Round(projectedArea, 2);//保留两位小数
            surfaceArea = Math.Round(surfaceArea, 2);
            volume = Math.Round(volume, 2);
        }