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();

         }