C#+arcengine获得栅格数据的像素值（高程）

 此文问获得栅格数据的像元值（即高程），有可能部分见解不到位，望大神看到了不惜指教！

  ///

        ///  得到高程（通过像素值）
        ///

        /// Raster路径
        private List GetElevation(string maskTifPath, List pointColList)//pointcollist是点集合，可以参照博文获得点集合

        {

            IRaster raster = GetRaster(maskTifPath);//参见博文获得raster数据
            //得到一段光栅带
            IRasterBandCollection rasterBandCollection = (IRasterBandCollection)raster;
            for (int icount = 0; icount < rasterBandCollection.Count; icount++)//测试数据count为1
            {
                IRasterBand rasterBand = rasterBandCollection.Item(icount);
                //像素
                IRawPixels rawPixels = (IRawPixels)rasterBand;
                IRasterProps rasterProps = (IRasterProps)rawPixels;
                //IGeoDataset geodataset = (IGeoDataset)raster;
                //IEnvelope2 envelop = new EnvelopeClass();
                //envelop = (IEnvelope2)geodataset.Extent;
                //IPoint point = envelop.UpperLeft;
                // 像元大致范围
                //double blockX = (double)rasterProps.MeanCellSize().X;//网格X间距
                //double blockY = (double)rasterProps.MeanCellSize().Y;//网格Y间距
                //double blockArea = blockX * blockY;//网格面积

                //int columns = rasterProps.Width;//dem列数
                //int rows = rasterProps.Height;//dem行数
                //   指定像素块大小
                IPnt blockSize = new DblPnt();
                //blockSize.X = columns;
                //blockSize.Y = rows;
                blockSize.X = 5;//赋值为多少比较合适？
                blockSize.Y = 5;
                //blockSize.X = blockX;
                //blockSize.Y = blockY;
                //指定像素块大小来创建像素快
                IPixelBlock3 pixelBlock = (IPixelBlock3)rawPixels.CreatePixelBlock(blockSize);
                IPnt blockOrigin = new DblPnt();
                IPoint point = new PointClass();
                List pixels = new List();
                for (int j = 0; j < pointColList.Count; j++)
                {
                    point = pointColList[j];
                    blockOrigin.X = point.X;
                    blockOrigin.Y = point.Y;
                    //   读取指定位置的像素块（blockOrigin为指定位置）
                    rawPixels.Read(blockOrigin, (IPixelBlock)pixelBlock);
                    //存储格网dem的二维数组
                    System.Array pixelData = (System.Array)pixelBlock.get_PixelDataByRef(icount);
                    // 获得每一个栅格的高程值
                    for (int col = 0; col < pixelData.GetLength(0); col++)
                    {
                        for (int row = 0; row < pixelData.GetLength(1); row++)
                        {
                            pixels.Add(Convert.ToInt32(pixelData.GetValue(col, row)));
                        }
                    }
                    return pixels;
                }
               
            }

        }

本博文参照http://www.docin.com/p-607056135.html，感谢！