private IDotDensityRenderer CreateRenderer()
{
IDotDensityRenderer pDotDensityRenderer = new DotDensityRendererClass();
IRendererFields pRendererFields = (IRendererFields)pDotDensityRenderer;
IDotDensityFillSymbol pDotDensityFillS = new DotDensityFillSymbolClass();
//pDotDensityFillS.DotSize = 2 * dotSize;
//pDotDensityFillS.Color = getRGB(0, 0, 0);
if (gColor != null)
{
pDotDensityFillS.BackgroundColor = gColor;
}
ISymbolArray pSymbolArray = (ISymbolArray)pDotDensityFillS;
string strField = string.Empty;
foreach (System.Collections.DictionaryEntry de in fieldSymbolHashTable)
{
strField = de.Key.ToString();;
ISymbol symbol = de.Value as ISymbol;
pRendererFields.AddField(strField, strField);
IMarkerSymbol pMarkerSymbol = symbol as IMarkerSymbol;
pMarkerSymbol.Size = dotSize;
pSymbolArray.AddSymbol(symbol);
}
pDotDensityRenderer.DotDensitySymbol = pDotDensityFillS;
pDotDensityRenderer.DotValue = dotValue;
pDotDensityRenderer.CreateLegend();
return(pDotDensityRenderer);
}
private void DotDensity(IFeatureLayer pFeatLyr, string sFieldName, int intRendererDensity)
{
IGeoFeatureLayer pGeoFeatureLayer = pFeatLyr as IGeoFeatureLayer;
IDotDensityRenderer pDotDensityRenderer = new DotDensityRendererClass();
IRendererFields pRendererFields = pDotDensityRenderer as IRendererFields;
//设置渲染字段
pRendererFields.AddField(sFieldName);
//设置填充背景色
IDotDensityFillSymbol pDotDensityFillSymbol = new DotDensityFillSymbolClass();
pDotDensityFillSymbol.DotSize = 3;
pDotDensityFillSymbol.BackgroundColor = GetRgbColor(0, 255, 0);
//设置渲染符号
ISymbolArray pSymbolArray = pDotDensityFillSymbol as ISymbolArray;
ISimpleMarkerSymbol pSimpleMarkerSymbol = new SimpleMarkerSymbolClass();
pSimpleMarkerSymbol.Style = esriSimpleMarkerStyle.esriSMSCircle;
pSimpleMarkerSymbol.Color = GetRgbColor(0, 0, 255);
pSymbolArray.AddSymbol(pSimpleMarkerSymbol as ISymbol);
pDotDensityRenderer.DotDensitySymbol = pDotDensityFillSymbol;
//设置渲染密度，即每个点符号所代表的数值大小
pDotDensityRenderer.DotValue = intRendererDensity;
//创建图例
pDotDensityRenderer.CreateLegend();
pGeoFeatureLayer.Renderer = pDotDensityRenderer as IFeatureRenderer;
axMapControl1.Refresh();
axMapControl1.Update();
Close();
}
/// <summary>
/// Dot Density Render
/// </summary>
/// <param name="currentLayer"></param>
/// <param name="breakCount"></param>
/// <author>Shen Yongyuan</author>
/// <date>20091114</date>
public static void DotDensityRender(ILayer currentLayer, string fieldName)
{
IGeoFeatureLayer pGeoFeatureL = currentLayer as IGeoFeatureLayer;
pGeoFeatureL.ScaleSymbols = true;
//Dot Density Render
IDotDensityRenderer pDotDensityRenderer = new DotDensityRendererClass();
IRendererFields pRendererFields = (IRendererFields)pDotDensityRenderer;
pRendererFields.AddField(fieldName, "生态");
//Dot Style
IDotDensityFillSymbol pDotDensityFillS = new DotDensityFillSymbolClass();
pDotDensityFillS.DotSize = 4;
pDotDensityFillS.Color = ArcGIS.Color.ToEsriColor(System.Drawing.Color.FromArgb(0, 0, 0));
pDotDensityFillS.BackgroundColor = ArcGIS.Color.ToEsriColor(System.Drawing.Color.FromArgb(239, 228, 190));
//Symbol Array
ISymbolArray pSymbolArray = (ISymbolArray)pDotDensityFillS;
ISimpleMarkerSymbol pSimpleMarkerS = new SimpleMarkerSymbolClass();
pSimpleMarkerS.Style = esriSimpleMarkerStyle.esriSMSCircle;
pSimpleMarkerS.Size = 4;
pSimpleMarkerS.Color = ArcGIS.Color.ToEsriColor(System.Drawing.Color.FromArgb(128, 128, 255));
pSymbolArray.AddSymbol((ISymbol)pSimpleMarkerS);
pDotDensityRenderer.DotDensitySymbol = pDotDensityFillS;
pDotDensityRenderer.DotValue = 0.05;
pDotDensityRenderer.CreateLegend();
pGeoFeatureL.Renderer = (IFeatureRenderer)pDotDensityRenderer;
}
//DotDensityFillSymbol
private void button8_Click(object sender, EventArgs e)
{
IGeoFeatureLayer geoFeatureLayer;
IDotDensityFillSymbol dotDensityFillSymbol;
IDotDensityRenderer dotDensityRenderer;
//获取渲染图层
geoFeatureLayer = getGeoLayer("Continents");
dotDensityRenderer = new DotDensityRendererClass();
IRendererFields rendererFields = dotDensityRenderer as IRendererFields;
//设置渲染字段
string field1 = "sqmi";
rendererFields.AddField(field1, field1);
//设置填充颜色和背景色
dotDensityFillSymbol = new DotDensityFillSymbolClass();
dotDensityFillSymbol.DotSize = 3;
dotDensityFillSymbol.Color = getRGB(255, 0, 0);
dotDensityFillSymbol.BackgroundColor = getRGB(0, 255, 0);
//设置渲染符号
ISymbolArray symbolArray = dotDensityFillSymbol as ISymbolArray;
ISimpleMarkerSymbol simpleMarkerSymbol = new SimpleMarkerSymbolClass();
simpleMarkerSymbol.Style = esriSimpleMarkerStyle.esriSMSCircle;
simpleMarkerSymbol.Size = 2;
simpleMarkerSymbol.Color = getRGB(0, 0, 255);
symbolArray.AddSymbol(simpleMarkerSymbol as ISymbol);
dotDensityRenderer.DotDensitySymbol = dotDensityFillSymbol;
//设置渲染密度
dotDensityRenderer.DotValue = 50000;
//创建图例
dotDensityRenderer.CreateLegend();
geoFeatureLayer.Renderer = dotDensityRenderer as IFeatureRenderer;
this.axMapControl1.Refresh();
}
/// <summary>
/// Occurs when this command is clicked
/// </summary>
public override void OnClick()
{
// TODO: Add DotDensityRender.OnClick implementation
string strPopField = "value";
IActiveView pActiveView = m_HookHelper.ActiveView;
IMap pMap = m_HookHelper.FocusMap;
IGeoFeatureLayer pGeoFeatureLayer = pMap.get_Layer(0) as IGeoFeatureLayer;
IDotDensityRenderer pDotDensityRenderer = new DotDensityRendererClass();
IRendererFields pRendererFields = (IRendererFields)pDotDensityRenderer;
pRendererFields.AddField(strPopField, strPopField);
IDotDensityFillSymbol pDotDensityFillSymbol = new DotDensityFillSymbolClass();
pDotDensityFillSymbol.DotSize = 5;
pDotDensityFillSymbol.Color = GetRGB(0, 0, 0);
pDotDensityFillSymbol.BackgroundColor = GetRGB(239, 228, 190);
ISymbolArray pSymbolArray = (ISymbolArray)pDotDensityFillSymbol;
ISimpleMarkerSymbol pSimpleMarkerSymbol = new SimpleMarkerSymbolClass();
pSimpleMarkerSymbol.Style = esriSimpleMarkerStyle.esriSMSCircle;
pSimpleMarkerSymbol.Size = 5;
pSimpleMarkerSymbol.Color = GetRGB(128, 128, 255);
pSymbolArray.AddSymbol((ISymbol)pSimpleMarkerSymbol);
pDotDensityRenderer.DotDensitySymbol = pDotDensityFillSymbol;
pDotDensityRenderer.DotValue = 0.5;
pDotDensityRenderer.CreateLegend();
pGeoFeatureLayer.Renderer = (IFeatureRenderer)pDotDensityRenderer;
pActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeography, null, null);
}
private void mnuDotDensity_Click(object sender, EventArgs e)
{
ILayer pLayer = MainMap.get_Layer(0);
ITable pTable = pLayer as ITable;
IGeoFeatureLayer pGeoFeatureLayer = pLayer as IGeoFeatureLayer;
IDotDensityRenderer pDotDensityRender = new DotDensityRendererClass();
IRendererFields pRendererFields = pDotDensityRender as IRendererFields;
pRendererFields.AddField("AREA");
// 建立一个用于填充的点符号
IDotDensityFillSymbol pDotDensityFillSymbol = new DotDensityFillSymbolClass();
pDotDensityFillSymbol.DotSize = 3;
IRgbColor pRgbColor = new RgbColorClass();
pRgbColor.Red = 0;
pRgbColor.Green = 0;
pRgbColor.Blue = 0;
IColor pColor = pRgbColor as IColor;
pDotDensityFillSymbol.Color = pColor;
pRgbColor = new RgbColorClass();
pRgbColor.Red = 239;
pRgbColor.Green = 228;
pRgbColor.Blue = 190;
pColor = pRgbColor as IColor;
pDotDensityFillSymbol.BackgroundColor = pColor;
ISymbolArray pSymbolArray = pDotDensityFillSymbol as ISymbolArray;
ISimpleMarkerSymbol pMarkerSymbol = new SimpleMarkerSymbolClass();
pMarkerSymbol.Style = esriSimpleMarkerStyle.esriSMSSquare;
pRgbColor = new RgbColorClass();
pRgbColor.Red = 0;
pRgbColor.Green = 0;
pRgbColor.Blue = 0;
pColor = pRgbColor as IColor;
pMarkerSymbol.Color = pColor;
pSymbolArray.AddSymbol(pMarkerSymbol as ISymbol);
// 开始着色
pDotDensityRender.DotDensitySymbol = pDotDensityFillSymbol;
pDotDensityRender.DotValue = 2;
pGeoFeatureLayer.Renderer = pDotDensityRender as IFeatureRenderer;
MainMap.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeography, null, null);
}
/// <summary>
/// 点状密度法渲染器(DotDensityRenderer)——在多边形特征中绘制不同密度的点
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void 点状密度法渲染ToolStripMenuItem_Click(object sender, EventArgs e)
{
//声明IGeoFeatureLayer变量, 提供一个要素图层对成员控制地理特征的入口
IGeoFeatureLayer geoFeatureLayer;
//定义点密度填充符号变量, 控制点符号的属性
IDotDensityFillSymbol dotDensityFillSymbol;
//定义点密度渲染对象
IDotDensityRenderer dotDensityRenderer;
//获取渲染图层
geoFeatureLayer = getGeoLayer("北部湾");
//实例化点密度渲染对象
dotDensityRenderer = new DotDensityRendererClass();
//强转点密度渲染对象并强转成渲染字段对象
IRendererFields rendererFields = dotDensityRenderer as IRendererFields;
//设置渲染字段
string field1 = "年";
//向渲染器添加字段(字段名、别名)
rendererFields.AddField(field1, field1);
//实例化点密度填充符号
dotDensityFillSymbol = new DotDensityFillSymbolClass();
dotDensityFillSymbol.DotSize = 4; //设置点的大小
dotDensityFillSymbol.Color = getRGB(0, 255, 0); //设置点的颜色
//将点密度填充符号强转为符号数组成员
ISymbolArray symbolArray = dotDensityFillSymbol as ISymbolArray;
//实例化简单标记符号
ISimpleMarkerSymbol simpleMarkerSymbol = new SimpleMarkerSymbolClass();
//设置点的符号为圆圈
simpleMarkerSymbol.Style = esriSimpleMarkerStyle.esriSMSCircle;
simpleMarkerSymbol.Size = 4; //设置大小
simpleMarkerSymbol.Color = getRGB(0, 255, 0); //设置颜色
//点符号的外边不填充颜色
simpleMarkerSymbol.OutlineColor = getNoRGB();
//将简单标记符号样式增加到符号数组成员中
symbolArray.AddSymbol(simpleMarkerSymbol as ISymbol);
//赋值点密度渲染(dotDensityRenderer)的点密度符号(DotDensitySymbol)属性
dotDensityRenderer.DotDensitySymbol = dotDensityFillSymbol;
//设置渲染密度
dotDensityRenderer.DotValue = 0.003;
//设置点密度填充符号的背景色
dotDensityFillSymbol.BackgroundColor = getRGB(255, 255, 255);
//创建图例
dotDensityRenderer.CreateLegend();
//赋值目标图层的渲染器属性
geoFeatureLayer.Renderer = dotDensityRenderer as IFeatureRenderer;
axMapControl1.Refresh(); //刷新axMapControl1
axTOCControl1.Update(); //更新axTOCControl1
}
public IDotDensityFillSymbol CreateDotDensityFillSymbol()
{
IDotDensityFillSymbol symbol = new DotDensityFillSymbolClass
{
DotSize = 2.0
};
IColor color = new RgbColorClass
{
NullColor = true
};
symbol.BackgroundColor = color;
return(symbol);
}
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); //ͬһ������Ľӿڵ��л����ܷ���ġ�
//this.pDotDensityFill = new DotDensityFillSymbolClass();
//pDotDensityFill.DotSize = 8;
//pDotDensityFill.Color = GetRGBColor(10, 20, 0);
//pDotDensityFill.BackgroundColor = GetRGBColor(100, 108, 190);
//pSymbolArry = pDotDensityFill as ISymbolArray;//�ѵ����ܶȡ�
//ISimpleMarkerSymbol pSimpleMark;
//pSimpleMark = new SimpleMarkerSymbolClass();
//pSimpleMark.Style = esriSimpleMarkerStyle.esriSMSDiamond;
//pSimpleMark.Size = 8;
//pSimpleMark.Color = GetRGBColor(128, 128, 255);
//pSymbolArry.AddSymbol(pSimpleMark as ISymbol);
//pDotDensityRenderer.DotDensitySymbol = pDotDensityFill;
//pDotDensityRenderer.DotValue = pValue;
//pDotDensityRenderer.CreateLegend();
//pGeoLayer.Renderer = (IFeatureRenderer)pDotDensityRenderer;
//pActiveView.Refresh();
//��ȡ��ǰͼ�� �����������ó�IGeoFeatureLayer��ʵ��
IMap pMap = pMapControl.Map;
// ILayer pFtLayer = pMap.get_Layer(0) as IFeatureLayer;
IFeatureLayer pFeatureLayer = pFtLayer as IFeatureLayer;
IGeoFeatureLayer pGeoFeatureLayer = pFtLayer as IGeoFeatureLayer;
//��ȡͼ���ϵ�feature
IFeatureClass pFeatureClass = pFeatureLayer.FeatureClass;
IFeatureCursor pFeatureCursor = pFeatureClass.Search(null, false);
IFeature pFeature = pFeatureCursor.NextFeature();
///////////////////////
///////////////////////////////////////////////////////////////////
//������ܶ�ͼ��Ⱦ���
IDotDensityRenderer DotDensityRenderer = new DotDensityRendererClass();
//������ܶ�ͼ��Ⱦ����������Ⱦ�ֶζ���
IRendererFields flds = (IRendererFields)DotDensityRenderer;
flds.AddField(pFieldName, pFieldName);
//flds.AddField("Shape", "Shape");
//������ܶ�ͼ��Ⱦ�÷��Ŷ���
IDotDensityFillSymbol ddSym = new DotDensityFillSymbolClass();
IRgbColor BackColor = new RgbColorClass();
BackColor.Red = 234;
BackColor.Blue = 128;
BackColor.Green = 220;
IRgbColor SymbolColor = new RgbColorClass();
SymbolColor.Red = 234;
SymbolColor.Blue = 128;
SymbolColor.Green = 220;
////���ܶ�ͼ��Ⱦ������ɫ
//ddSym.BackgroundColor = BackColor;
ddSym.DotSize = 8;
ddSym.FixedPlacement = true;
//ddSym.Color = SymbolColor;
ILineSymbol pLineSymbol = new CartographicLineSymbolClass();
ddSym.Outline = pLineSymbol;
//�����������
ISymbolArray symArray = (ISymbolArray)ddSym;
//��ӵ��ܶ�ͼ��Ⱦ�ĵ���ŵ�����������ȥ
ISimpleMarkerSymbol pMarkerSymbol = new SimpleMarkerSymbolClass();
pMarkerSymbol.Style = esriSimpleMarkerStyle.esriSMSCircle;
pMarkerSymbol.Size = 0.2;
pMarkerSymbol.Color = SymbolColor; ;
symArray.AddSymbol(pMarkerSymbol as ISymbol);
//���õ��ܶ�ͼ��Ⱦ�ĵ����
//DotDensityRenderer.DotDensitySymbol =symArray;
DotDensityRenderer.DotDensitySymbol = ddSym;
//ȷ��һ����������ֵ
DotDensityRenderer.DotValue = pValue;
//���ܶ���Ⱦ���õ���ɫģʽ
DotDensityRenderer.ColorScheme = "Custom";
//�������ܶ�ͼ��Ⱦͼ��
DotDensityRenderer.CreateLegend();
//���÷��Ŵ�С�Ƿ�̶�
DotDensityRenderer.MaintainSize = true;
//�����ܶ�ͼ��Ⱦ��������Ⱦͼ��ҹ�
pGeoFeatureLayer.Renderer = (IFeatureRenderer)DotDensityRenderer;
//ˢ�µ�ͼ��TOOCotrol
IActiveView pActiveView = pMap as IActiveView;
pActiveView.Refresh();
}
private IDotDensityRenderer CreateRenderer()
{
IDotDensityRenderer pDotDensityRenderer = new DotDensityRendererClass();
IRendererFields pRendererFields = (IRendererFields)pDotDensityRenderer;
IDotDensityFillSymbol pDotDensityFillS = new DotDensityFillSymbolClass();
//pDotDensityFillS.DotSize = 2 * dotSize;
//pDotDensityFillS.Color = getRGB(0, 0, 0);
if (gColor != null)
pDotDensityFillS.BackgroundColor = gColor;
ISymbolArray pSymbolArray = (ISymbolArray)pDotDensityFillS;
string strField = string.Empty;
foreach (System.Collections.DictionaryEntry de in fieldSymbolHashTable)
{
strField = de.Key.ToString(); ;
ISymbol symbol = de.Value as ISymbol;
pRendererFields.AddField(strField, strField);
IMarkerSymbol pMarkerSymbol = symbol as IMarkerSymbol;
pMarkerSymbol.Size = dotSize;
pSymbolArray.AddSymbol(symbol);
}
pDotDensityRenderer.DotDensitySymbol = pDotDensityFillS;
pDotDensityRenderer.DotValue = dotValue;
pDotDensityRenderer.CreateLegend();
return pDotDensityRenderer;
}
//DotDensityFillSymbol圆点密度图
private void button8_Click(object sender, EventArgs e)
{
IGeoFeatureLayer geoFeatureLayer;
IDotDensityFillSymbol dotDensityFillSymbol;
IDotDensityRenderer dotDensityRenderer;
//获取渲染图层
geoFeatureLayer = getGeoLayer("Continents");
dotDensityRenderer = new DotDensityRendererClass();
IRendererFields rendererFields = dotDensityRenderer as IRendererFields;
//设置渲染字段
string field1 = "sqmi";
rendererFields.AddField(field1, field1);
//设置填充颜色和背景色
dotDensityFillSymbol = new DotDensityFillSymbolClass();
dotDensityFillSymbol.DotSize = 3;
dotDensityFillSymbol.Color = getRGB(255, 0, 0);
dotDensityFillSymbol.BackgroundColor = getRGB(0, 255, 0);
//设置渲染符号
ISymbolArray symbolArray = dotDensityFillSymbol as ISymbolArray;
ISimpleMarkerSymbol simpleMarkerSymbol = new SimpleMarkerSymbolClass();
simpleMarkerSymbol.Style = esriSimpleMarkerStyle.esriSMSCircle;
simpleMarkerSymbol.Size = 2;
simpleMarkerSymbol.Color = getRGB(0, 0, 255);
symbolArray.AddSymbol(simpleMarkerSymbol as ISymbol);
dotDensityRenderer.DotDensitySymbol = dotDensityFillSymbol;
//设置渲染密度
dotDensityRenderer.DotValue = 50000;
//创建图例
dotDensityRenderer.CreateLegend();
geoFeatureLayer.Renderer = dotDensityRenderer as IFeatureRenderer;
this.axMapControl1.Refresh();
}
private void btnDotDensityRender_Click(object sender, EventArgs e)
{
IGeoFeatureLayer pGeoFeatLyr = this.mainMapControl.get_Layer(0) as IGeoFeatureLayer;
//创建SimpleMarkerSymbol,将会用在DotDensitySymbol中
IMarkerSymbol pMarkerSymbol = new SimpleMarkerSymbolClass();
pMarkerSymbol.Color = getRGBColor(255, 0, 0);
//创建并设置DotDensitySymbol,以及DotDensitySymbol中的Symbol(上面的MarkerSymbol)
IDotDensityFillSymbol pDotDensityFillSymbol = new DotDensityFillSymbolClass();
pDotDensityFillSymbol.DotSize = 5;//大小
pDotDensityFillSymbol.Color = getRGBColor(0, 255, 0);//此颜色不知为何物???????????
pDotDensityFillSymbol.BackgroundColor = getRGBColor(239, 228, 190);
ISymbolArray pSymbolArray = pDotDensityFillSymbol as ISymbolArray;
pSymbolArray.AddSymbol((ISymbol)pMarkerSymbol);//添加符号,关键
//以下创建并设置着色对象
IDotDensityRenderer pDotDensityRenderer = new DotDensityRendererClass();
pDotDensityRenderer.DotDensitySymbol = pDotDensityFillSymbol;//着色对象所用的DotDensitySymbol
pDotDensityRenderer.DotValue = 100;//一个点代表的值,关键!!!
pDotDensityRenderer.MaintainSize = true;//地图缩放时DotDensitySymbol符号大小保持
IRendererFields pRendererFields = pDotDensityRenderer as IRendererFields;
pRendererFields.AddField("GDP_1999（", "GDP_1999（");//用于着色的字段,关键
pDotDensityRenderer.CreateLegend();
pGeoFeatLyr.Renderer = pDotDensityRenderer as IFeatureRenderer;
this.mainMapControl.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeography, null, null);
this.axTOCControl.Update();
}
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 = 8;
//pDotDensityFill.Color = GetRGBColor(10, 20, 0);
//pDotDensityFill.BackgroundColor = GetRGBColor(100, 108, 190);
//pSymbolArry = pDotDensityFill as ISymbolArray;//难道是密度。
//ISimpleMarkerSymbol pSimpleMark;
//pSimpleMark = new SimpleMarkerSymbolClass();
//pSimpleMark.Style = esriSimpleMarkerStyle.esriSMSDiamond;
//pSimpleMark.Size = 8;
//pSimpleMark.Color = GetRGBColor(128, 128, 255);
//pSymbolArry.AddSymbol(pSimpleMark as ISymbol);
//pDotDensityRenderer.DotDensitySymbol = pDotDensityFill;
//pDotDensityRenderer.DotValue = pValue;
//pDotDensityRenderer.CreateLegend();
//pGeoLayer.Renderer = (IFeatureRenderer)pDotDensityRenderer;
//pActiveView.Refresh();
//获取当前图层 ，并把它设置成IGeoFeatureLayer的实例
IMap pMap = pMapControl.Map;
// ILayer pFtLayer = pMap.get_Layer(0) as IFeatureLayer;
IFeatureLayer pFeatureLayer = pFtLayer as IFeatureLayer;
IGeoFeatureLayer pGeoFeatureLayer = pFtLayer as IGeoFeatureLayer;
//获取图层上的feature
IFeatureClass pFeatureClass = pFeatureLayer.FeatureClass;
IFeatureCursor pFeatureCursor = pFeatureClass.Search(null, false);
IFeature pFeature = pFeatureCursor.NextFeature();
///////////////////////
///////////////////////////////////////////////////////////////////
//定义点密度图渲染组件
IDotDensityRenderer DotDensityRenderer = new DotDensityRendererClass();
//定义点密度图渲染组件对象的渲染字段对象
IRendererFields flds = (IRendererFields)DotDensityRenderer;
flds.AddField(pFieldName, pFieldName);
//flds.AddField("Shape", "Shape");
//定义点密度图渲染得符号对象
IDotDensityFillSymbol ddSym = new DotDensityFillSymbolClass();
IRgbColor BackColor = new RgbColorClass();
BackColor.Red = 234;
BackColor.Blue = 128;
BackColor.Green = 220;
IRgbColor SymbolColor = new RgbColorClass();
SymbolColor.Red = 234;
SymbolColor.Blue = 128;
SymbolColor.Green = 220;
////点密度图渲染背景颜色
//ddSym.BackgroundColor = BackColor;
ddSym.DotSize = 8;
ddSym.FixedPlacement = true;
//ddSym.Color = SymbolColor;
ILineSymbol pLineSymbol = new CartographicLineSymbolClass();
ddSym.Outline = pLineSymbol;
//定义符号数组
ISymbolArray symArray = (ISymbolArray)ddSym;
//添加点密度图渲染的点符号到符号数组中去
ISimpleMarkerSymbol pMarkerSymbol = new SimpleMarkerSymbolClass();
pMarkerSymbol.Style = esriSimpleMarkerStyle.esriSMSCircle;
pMarkerSymbol.Size = 0.2;
pMarkerSymbol.Color = SymbolColor;;
symArray.AddSymbol(pMarkerSymbol as ISymbol);
//设置点密度图渲染的点符号
//DotDensityRenderer.DotDensitySymbol =symArray;
DotDensityRenderer.DotDensitySymbol = ddSym;
//确定一个点代表多少值
DotDensityRenderer.DotValue = pValue;
//点密度渲染采用的颜色模式
DotDensityRenderer.ColorScheme = "Custom";
//创建点密度图渲染图例
DotDensityRenderer.CreateLegend();
//设置符号大小是否固定
DotDensityRenderer.MaintainSize = true;
//将点密度图渲染对象与渲染图层挂钩
pGeoFeatureLayer.Renderer = (IFeatureRenderer)DotDensityRenderer;
//刷新地图和TOOCotrol
IActiveView pActiveView = pMap as IActiveView;
pActiveView.Refresh();
}