ArcGIS Engine 10 开发手册(7-12)ArcGIS Engine中点状图的调用

    本文介绍使用ArcGIS Engine生成点状图的方法。

   ArcGIS Engine生成点状图示例代码

    代码如下：

public class DotRender

{

  IGeoFeatureLayer pGeoLayer;

  IDotDensityRenderer pDotDensityRenderer; //渲染对象

  IDotDensityFillSymbol pDotDensityFill; //渲染填充符号对象,大对象分解小对象, 独立的可看作对象。

  IRendererFields pRendFields; //用那个字段渲染。理解层次关系。

  ISymbolArray pSymbolArry;

  public DotRender (AxMapControl pMapControl, IFeatureLayer pFtLayer, double pValue, string pFieldName)

  {

    IActiveView pActiveView;

    this.pGeoLayer = pFtLayer as IGeoFeatureLayer;

    pActiveView = pMapControl.ActiveView;

    pDotDensityRenderer = new DotDensityRendererClass ();

    pRendFields = pDotDensityRenderer as IRendererFields;

    pRendFields.AddField (pFieldName, pFieldName); //同一个对象的接口的切换,很方便的。

    this.pDotDensityFill = new DotDensityFillSymbolClass ();

    pDotDensityFill.DotSize = 2.46;

    pDotDensityFill.Color = GetRGBColor (0, 100, 0);

    pDotDensityFill.BackgroundColor = GetRGBColor (255, 255, 255);

    pSymbolArry = pDotDensityFill as ISymbolArray; //难道是密度。

    ISimpleMarkerSymbol pSimpleMark;

    pSimpleMark = new SimpleMarkerSymbolClass ();

    pSimpleMark.Style = esriSimpleMarkerStyle.esriSMSDiamond;

    pSimpleMark.Size = 2.46;

    pSimpleMark.Color = GetRGBColor (235, 190, 89);

    pSymbolArry.AddSymbol (pSimpleMark as ISymbol);

    pDotDensityRenderer.DotDensitySymbol = pDotDensityFill;

    pDotDensityRenderer.DotValue = pValue;

    pDotDensityRenderer.CreateLegend ();

    pGeoLayer.Renderer = (IFeatureRenderer) pDotDensityRenderer;

    pActiveView.PartialRefresh (esriViewDrawPhase.esriViewGeography, null, null);

  }

  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