C#+arcengine实现栅格计算器的减功能（可以用来修改栅格数据的高程）

此文为利用栅格计算器改变raster的高程的功能，具体如下：

  ///

        /// 更改栅格影像的高程
        ///

        /// 裁剪后的raster

        /// 高程众数（你想把高程减去的数）

       /// 要输出的raster的路径

        private void SetRasterElevation(string inClipRaster, string outRasterPath, int elevationMode)
        {
            try
            {
                //输出路径和名称
                int iindx = outRasterPath.LastIndexOf("\\");
                //输出raster的名称
                string suffixRasterName = (outRasterPath.Substring(iindx + 1));
                //输出raster的路径（无名称）
                string rasterPath = outRasterPath.Remove(iindx);
                //得到raster
                IRaster raster = GetRaster(inClipRaster);
                //控制地图代数的操作
                IMapAlgebraOp mapAlgebraOp;
                mapAlgebraOp = new RasterMapAlgebraOpClass();
                //控制raster分析的环境
                IRasterAnalysisEnvironment rasterAnalysisEnvironment = default(IRasterAnalysisEnvironment);
                rasterAnalysisEnvironment = (IRasterAnalysisEnvironment)mapAlgebraOp;
                //设置工作空间
                IWorkspaceFactory workspaceFactory = new RasterWorkspaceFactoryClass();
                IWorkspace workspace = workspaceFactory.OpenFromFile(rasterPath, 0);//这里应该是输出raster的路径
                rasterAnalysisEnvironment.OutWorkspace = workspace;
                //在地理数据集中绑定栅格数据

                //GeoDataset可以是输入的raster、rasterDataset、RasterBand、RasterDescriptor；clipRaster应该是要修改的栅格数据的名称（string），（这里我的名称是固定的clipRaster）

                mapAlgebraOp.BindRaster((IGeoDataset)raster, "clipRaster");
                //定义表达式（elevationMode为要减去的数值）不要忘了"[ ]"
                string strOut = "[clipRaster] " + " -  " + elevationMode;
                //执行表达式
                IRaster outRaster = (IRaster)mapAlgebraOp.Execute(strOut);
                //保存
                ISaveAs2 saveAs;
                saveAs = (ISaveAs2)outRaster;
                saveAs.SaveAs(suffixRasterName, workspace, "TIFF");//输出名称(注意：名称中加后缀名，例：test.tif)，工作空间，格式
                MessageBox.Show("栅格计算器成功！");
            }
            catch (Exception ex)
            {
                MessageBox.Show("栅格计算器失败！");
                Console.WriteLine(ex.Message);
            }
        }