[转]c# 栅格运算 获得一副DEM地图某个高度以下的范围,并显示

IRaster pRaster = pRasLyr.Raster;  //获取已知栅格图层pRasLyr的栅格对象
                IGeoDataset tempGeodata = pRaster as IGeoDataset;
                IMapAlgebraOp rsalgebra = new RasterMapAlgebraOpClass();
                //设置栅格运算空间
                IRasterAnalysisEnvironment rasAnaEnv = (IRasterAnalysisEnvironment)rsalgebra;
                IWorkspaceFactory wsf = new RasterWorkspaceFactoryClass();
                IWorkspace ws = wsf.OpenFromFile("F:\\beifen\\jg", 0);
                rasAnaEnv.OutWorkspace = ws;
                rsalgebra.BindRaster(tempGeodata, "tempRaster");
                //进行栅格运算,height为已知的整型数据,用来确定高度
               string Opstr = "[tempRaster] < " + height.ToString();
                IGeoDataset outGeoDataset = rsalgebra.Execute( Opstr );

                IRasterLayer pCreatRslyr = new RasterLayerClass();
                pCreatRslyr.CreateFromRaster((IRaster)outGeoDataset);
                RasterRender(ref pCreatRslyr);   //对生成的栅格图层进行渲染,是满足要求的按一个颜色显示,不满足要求的栅格不显示
                m_map.AddLayer(pCreatRslyr);
         //
        //栅格图的渲染
        //
        public void RasterRender(ref IRasterLayer pRasterLayer)
        {
            int NumOfClass = 2;
            IRaster pRaster;
            pRaster = pRasterLayer.Raster;

            //Create classfy renderer and QI RasterRenderer interface
            IRasterClassifyColorRampRenderer pClassRen = new RasterClassifyColorRampRendererClass();

            IRasterRenderer pRasRen = pClassRen as IRasterRenderer;
            pRasRen.Raster = pRaster;
            //字串5 
            //Set raster for the render and update

            pClassRen.ClassCount = NumOfClass;


            pRasRen.Update();

            // Create a color ramp to use
            IAlgorithmicColorRamp pRamp = new AlgorithmicColorRamp();

            pRamp.Size = NumOfClass;
            IRgbColor pFColor = new RgbColorClass();
            IRgbColor pTColor = new RgbColorClass();


            pFColor.NullColor = true;
            pTColor.RGB = 100;

            pRamp.FromColor = pFColor;
            pRamp.ToColor = pTColor;
            bool ok = true;
            pRamp.CreateRamp(out ok);

            // Create symbol for the classes 字串2 
            IFillSymbol pFSymbol = new SimpleFillSymbolClass();



            //Update the renderer and plug into layer
            pFSymbol.Color = pFColor;
            ISymbol pSmbol1 = pFSymbol as ISymbol;
            pClassRen.set_Symbol(0, pSmbol1);
            pFSymbol.Color = pTColor;
            ISymbol pSmbol2 = pFSymbol as ISymbol;
            pClassRen.set_Symbol(1, pSmbol2);
            pRasRen.Update();

            pRasterLayer.Renderer = pClassRen as IRasterRenderer; 
        } 
 

你可能感兴趣的:(C++,c,F#,C#)