Engine中数据进行分级渲染时如何获取各个自然间断点的数值？

【解决办法】：
获取间断点主要是IClassifyGEN接口，不过栅格和矢量数据获取唯一值和个数的方法不同；
栅格数据可以通过IRasterCalcUniqueValues获取唯一值，矢量数据可以通过IBasicHistogram获取。可参考下面代码：

//矢量要素类分级渲染

ITableHistogram tableHistogram = new BasicTableHistogramClass();

            IBasicHistogram basicHistogram = tableHistogram as IBasicHistogram;

            tableHistogram.Table = FC as ITable;

            tableHistogram.Field = GiZScore;//分类字段

            object dataValues;

            object dataFrequent;

            int classCount=5;

            double[] classes;

            basicHistogram.GetHistogram(out dataValues, out dataFrequent);

            IClassifyGEN classifyGEN = new NaturalBreaksClass();

            classifyGEN.Classify(dataValues, dataFrequent, ref classCount);

            classes = (double[])classifyGEN.ClassBreaks;



//栅格数据分级渲染

IUniqueValues uniVal = new UniqueValuesClass();

            IRasterCalcUniqueValues rasterUnique = new RasterCalcUniqueValuesClass();

            rasterUnique.AddFromRaster(Raster, 0, uniVal);

            object vValues, vFrequences;

            uniVal.GetHistogram(out vValues, out vFrequences);           

            IClassifyGEN pClassifyGEN = new NaturalBreaksClass();

            int classCount = 5;

            pClassifyGEN.Classify(vValues, vFrequences, ref classCount);

            double[] classes = pClassifyGEN.ClassBreaks as double[];