DotDensityRenderer

关键之处在于获取每个点所代表的的值 这里使用geodatabase类库中idatastatistic接口进行统计字段，再将结果传递给esrisysytem.istatisticsResult进行.

需用到引用

 using ESRI.ArcGIS.Display;
 using ESRI.ArcGIS.Carto;
 using ESRI.ArcGIS.esriSystem;
 using ESRI.ArcGIS.Geodatabase;

代码

 private void dotToolStripMenuItem_Click(object sender, EventArgs e)
         {
 IGeoFeatureLayer pLayer = this.axMapControl1.get_Layer()as IGeoFeatureLayer;
             ITable pTable = pLayer.FeatureClass as ITable;
             IQueryFilter pQueryFilter=new QueryFilterClass();
             pQueryFilter.AddField("PERIMETER");
             ICursor pCursor = pTable.Search(pQueryFilter, true);
             IDataStatistics pDataStatistics = new DataStatisticsClass();
             pDataStatistics.Cursor = pCursor;//数据来源
             pDataStatistics.Field = "PERIMETER";
             IStatisticsResults pStatisticsResult = pDataStatistics.Statistics;
             double Dvalues = (pStatisticsResult.Minimum+pStatisticsResult.Maximum)/;//根据情况而定

             IDotDensityRenderer pDotDensityRenderer=new DotDensityRendererClass();

             IRendererFields pRendererField = pDotDensityRenderer as IRendererFields;
             pRendererField.AddField("PERIMETER", "PERIMETER");

             IDotDensityFillSymbol pDotDensityFillSymbol = new DotDensityFillSymbolClass();
             pDotDensityFillSymbol.DotSize =;
             pDotDensityFillSymbol.BackgroundColor = GetRgbColor(, , );
             pDotDensityFillSymbol.Color = GetRgbColor(, , );

             ISymbolArray pSymbolArray = pDotDensityFillSymbol as ISymbolArray;
             ISimpleMarkerSymbol pMarkerSymbol = new SimpleMarkerSymbolClass();
             pMarkerSymbol.Color = GetRgbColor(, , );
             pMarkerSymbol.Style = esriSimpleMarkerStyle.esriSMSDiamond;
             pMarkerSymbol.Size = ;
             pSymbolArray.AddSymbol(pMarkerSymbol as ISymbol);

             pDotDensityRenderer.DotDensitySymbol = pDotDensityFillSymbol;
             pDotDensityRenderer.DotValue = Dvalues;
             pDotDensityRenderer.CreateLegend();

             pLayer.Renderer = pDotDensityRenderer as IFeatureRenderer;
             this.axMapControl1.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeography, null, null);
             this.axTOCControl1.Update();

         }