ArcGIS Engine 10 开发手册(7-11)ArcGIS Engine中饼图的调用

    本文介绍使用ArcGIS Engine生成饼图的方法。

   ArcGIS Engine生成饼图示例代码

    代码如下：

public PieRender (AxMapControl pMapcontrol, IFeatureLayer pFtLayer, string pFieldName1, string pFieldName2)

{

  IGeoFeatureLayer pGeoFeaLayer = (IGeoFeatureLayer) pFtLayer;

  IChartRenderer pChartRenderer = new ChartRendererClass ();

  // Set up the field to draw charts

  IRendererFields pRenderFields = (IRendererFields) pChartRenderer;

  pRenderFields.AddField (pFieldName1, pFieldName1);

  pRenderFields.AddField (pFieldName2, pFieldName2);

  IPieChartRenderer pPieChartRender = (IPieChartRenderer) pChartRenderer;

  //计算最大值部分有待补充////////////////////////////////////

  //Calculate the max value of the data field to scale the chart

  //ICursor pCursor = new CursorClass();

  IQueryFilter pQueryFilter = new QueryFilterClass ();

  //IRowBuffer pRow = new RowBufferClass();

  ITable pTable = (ITable) pGeoFeaLayer;

  pQueryFilter.AddField (pFieldName1);

  ICursor pCursor = pTable.Search (pQueryFilter, true);

  IDataStatistics pDataStat = new DataStatisticsClass ();

  IFeatureCursor pFtCursor = pFtLayer.FeatureClass.Search (null, false);

  pDataStat.Cursor = pFtCursor as ICursor;

  pDataStat.Field = pFieldName1;

  double pMax = pDataStat.Statistics.Maximum;

  IPieChartSymbol pPiechartSymbol = new PieChartSymbolClass ();

  IFillSymbol pFillSymbol = new SimpleFillSymbolClass ();

  IChartSymbol pChartSymbol = (IChartSymbol) pPiechartSymbol;

  pPiechartSymbol.Clockwise = true;

  pPiechartSymbol.UseOutline = true;

  ILineSymbol pOutLine = new SimpleLineSymbolClass ();

  pOutLine.Color = GetRGBColor (255, 0, 255);

  pOutLine.Width = 1;

  pPiechartSymbol.Outline = pOutLine;

  IMarkerSymbol pMarkerSymbol = (IMarkerSymbol) pPiechartSymbol;

  //finally

  pChartSymbol.MaxValue = pMax;

  pMarkerSymbol.Size = 16;

  //像符号数组中添加 添加符号

  ISymbolArray pSymbolArray = (ISymbolArray) pPiechartSymbol;

  pFillSymbol.Color = GetRGBColor (213, 212, 252);

  pFillSymbol.Outline = pOutLine;

  pSymbolArray.AddSymbol ((ISymbol) pFillSymbol);

  //////////////////////////

  pFillSymbol.Color = GetRGBColor (183, 242, 122);

  pFillSymbol.Outline = pOutLine;

  pSymbolArray.AddSymbol ((ISymbol) pFillSymbol);

  //set up the background

  pFillSymbol.Color = GetRGBColor (239, 228, 190);

  pChartRenderer.BaseSymbol = (ISymbol) pFillSymbol;

  pChartRenderer.UseOverposter = false;

  pPieChartRender.MinSize = 1;

  pPieChartRender.MinValue = pDataStat.Statistics.Minimum;

  pPieChartRender.FlanneryCompensation = false;

  pPieChartRender.ProportionalBySum = true;

  pChartRenderer.ChartSymbol = (IChartSymbol) pPiechartSymbol;

  pChartRenderer.CreateLegend ();

  pGeoFeaLayer.Renderer = (IFeatureRenderer) pChartRenderer;

  pMapcontrol.ActiveView.Refresh ();

}

public IRgbColor GetRGBColor (int r, int g, int b)

{

  IRgbColor pRGB;

  pRGB = new RgbColorClass ();

  pRGB.Red = r;

  pRGB.Green = g;

  pRGB.Blue = b;

  return pRGB;

}

     效果如图