AE 栅格图分级渲染

转自 AE 栅格图分级渲染

ArcEngine对矢量数据进行风格化实在是得心应手，同样的对于栅格图像也能进行风格化！以前没接触过，今天正好需要，做出了栅格图像的渲染！下面实现的思路：

1.定义渲染的一系列接口

2.判断图像是否建立了直方图，如果没有则进行创建。

3.定义颜色序列，为渲染提供渲染的方案。

4.调用Render方法进行渲染。

下面是代码：有两个方法，一个是加载栅格数据，一个是进行渲染，接着在事件里面调用方法，实现图像渲染！

        /// 栅格分类专题图
        ///
        /// 栅格图层
        public static void funColorForRaster_Classify(IRasterLayer pRasterLayer)
        {
            IRasterClassifyColorRampRenderer pRClassRend = new RasterClassifyColorRampRenderer() as IRasterClassifyColorRampRenderer;
            IRasterRenderer pRRend = pRClassRend as IRasterRenderer;
 
            IRaster pRaster = pRasterLayer.Raster;
            IRasterBandCollection pRBandCol = pRaster as IRasterBandCollection;
            IRasterBand pRBand = pRBandCol.Item(0);
            if (pRBand.Histogram == null)
            {
                pRBand.ComputeStatsAndHist();
            }
            pRRend.Raster = pRaster;
            pRClassRend.ClassCount = 10;
            pRRend.Update();
 
            IRgbColor pFromColor = new RgbColor() as IRgbColor;
            pFromColor.Red = 255;
            pFromColor.Green = 0;
            pFromColor.Blue = 0;
            IRgbColor pToColor = new RgbColor() as IRgbColor;
            pToColor.Red = 0;
            pToColor.Green = 0;
            pToColor.Blue = 255;
 
            IAlgorithmicColorRamp colorRamp = new AlgorithmicColorRamp() as IAlgorithmicColorRamp;
            colorRamp.Size = 10;
            colorRamp.FromColor = pFromColor;
            colorRamp.ToColor = pToColor;          
            bool createColorRamp;
 
            colorRamp.CreateRamp(out createColorRamp);
 
            IFillSymbol fillSymbol = new SimpleFillSymbol() as IFillSymbol;
            for (int i = 0; i < pRClassRend.ClassCount; i++)
            {
                fillSymbol.Color = colorRamp.get_Color(i);
                pRClassRend.set_Symbol(i, fillSymbol as ISymbol);
                pRClassRend.set_Label(i, pRClassRend.get_Break(i).ToString("0.00"));
            }
            pRasterLayer.Renderer = pRRend;
        }
        
        ///
        /// 打开遥感图像
        ///
        /// 图像的地址
        /// IRasterLayer
        private IRasterLayer OpenImage(string imagePath)
        {
            string ws = Path.GetDirectoryName(imagePath);
            string fbs = Path.GetFileName(imagePath);
 
            IWorkspaceFactory pWork = new RasterWorkspaceFactory();
            IRasterWorkspace pRasterWs = pWork.OpenFromFile(ws,0) as IRasterWorkspace;
            IRasterDataset pRasterDataset = pRasterWs.OpenRasterDataset(fbs);
            
            IRasterLayer pRasterLayer = new RasterLayer() as IRasterLayer;
            pRasterLayer.CreateFromDataset(pRasterDataset);
            return pRasterLayer;            
        }

事件的逻辑:

axMapControl1.Map.AddLayer(OpenImage(filePath));

axMapControl1.ActiveView.Refresh();

funColorForRaster_Classify(axMapControl1.get_layer(0) as IRasterLayer);//only one RasterLayer

axMapControl1.Activeview.Refresh();

下面是渲染前后的效果图：