ArcEngine 产生专题图
ArcEngine提供多个着色对象用于产生专题图，可以使用标准着色方案，也可以自定义着色方案，ArcEngine提供8中标准着色方案。
一、SimpleRenderer专题图
是使用单一符号进行着色分类，不涉及对要素的数据进行处理。这种专题图同一个图层内的所有元素都是一种符号。
通过SimpleRenderer对象对Symbol进行设置后，赋予IGeoFeatureLayer接口的Renderer属性，对象实现了ITransparencyRenerer接口，通过该接口的属性，可以根据要素的某一个数值字段来设置要素显示的透明度。
该对象还实现了ISimpleRenderer接口，提供了两个重要的属性：Description和Label这两个属性用来设置图例。
/// <summary>
/// 简单渲染
/// </summary>
/// <param name="layerName">图层名字</param>
/// <param name="FillStyle">FillStyle</param>
/// <param name="pColor">FillColor</param>
/// <param name="OutLineColor">OutLineColor</param>
/// <param name="RenderLabel">样式名称注释</param>
/// <param name="Descripition">描述</param>
public void createSimpleFillSymbol(string layerName,esriSimpleFillStyle FillStyle,IColor pColor,IColor OutLineColor,string RenderLabel,string Descripition)
{
//简单填充符号
ISimpleFillSymbol simpleFillSymbol = new SimpleFillSymbolClass();
//可以用符号选择器进行
simpleFillSymbol.Style = FillStyle;
simpleFillSymbol.Color = pColor;
//创建边线符号
ISimpleLineSymbol simpleLineSymbol = new SimpleLineSymbolClass();
simpleLineSymbol.Style = esriSimpleLineStyle.esriSLSSolid;
simpleLineSymbol.Color = OutLineColor;
ISymbol symbol = simpleLineSymbol as ISymbol;
symbol.ROP2 = esriRasterOpCode.esriROPNotXOrPen;
simpleFillSymbol.Outline = simpleLineSymbol;
ISimpleRenderer simpleRender = new SimpleRendererClass();
simpleRender.Symbol = simpleFillSymbol as ISymbol;
simpleRender.Label = RenderLabel;
simpleRender.Description = Descripition;
IGeoFeatureLayer geoFeatureLayer;
geoFeatureLayer = getGeoLayer(layerName);
if (geoFeatureLayer != null)
{
geoFeatureLayer.Renderer = simpleRender as IFeatureRenderer;
}
}
二、ClassBreakRenderer专题图
为分级专题图，通过要素图层中要素的某个数值字段的值，根据用户要求，将这些值分为多个级别，每个级别用不同的Symbol显示。
该对象实现了IClassBreakRenderer接口，提供了实现分级显示的属性和方法，如Field属性用于设置分级着色的字段，BreakCount属性用于设置分级的数目。
/// <summary>
/// 分级渲染
/// </summary>
/// <param name="layerName">图层名</param>
/// <param name="classCount">分级数目</param>
/// <param name="ClassField">分级字段</param>
/// <param name="FillStyle">填充样式</param>
public void createClassBreakRender(string layerName, int classCount, string ClassField, esriSimpleFillStyle FillStyle)
{
//int classCount = 6;
ITableHistogram tableHistogram;//表格直方图
IBasicHistogram basicHistogram;//Provides access to members that control histogram objects created from different data sources.
ITable table;
IGeoFeatureLayer geoFeatureLayer;
geoFeatureLayer = getGeoLayer(layerName);
ILayer layer = geoFeatureLayer as ILayer;
table = layer as ITable;
tableHistogram = new BasicTableHistogramClass();
//按照 数值字段分级
tableHistogram.Table = table;
tableHistogram.Field = ClassField;
basicHistogram = tableHistogram as IBasicHistogram;
object values;
object frequencys;
//先统计每个值和各个值出现的次数
basicHistogram.GetHistogram(out values, out frequencys);
//创建平均分级对象
IClassifyGEN classifyGEN = new QuantileClass();
//用统计结果进行分级 ，级别数目为classCount
classifyGEN.Classify(values, frequencys, ref classCount);
//获得分级结果,是个 双精度类型数组
double[] classes;
classes = classifyGEN.ClassBreaks as double[];
//定义不同等级渲染的色带用色
IEnumColors enumColors = CreateAlgorithmicColorRamp(classes.Length).Colors;
IColor color;
IClassBreaksRenderer classBreaksRenderer = new ClassBreaksRendererClass();
classBreaksRenderer.Field = ClassField;
classBreaksRenderer.BreakCount = classCount;//分级数目
classBreaksRenderer.SortClassesAscending = true;//定义分类是否在TOC中显示Legend
ISimpleFillSymbol simpleFillSymbol;
for (int i = 0; i < classes.Length - 1; i++)
{
color = enumColors.Next();
simpleFillSymbol = new SimpleFillSymbolClass();
simpleFillSymbol.Color = color;
simpleFillSymbol.Style = FillStyle;
classBreaksRenderer.set_Symbol(i, simpleFillSymbol as ISymbol);
classBreaksRenderer.set_Break(i, classes[i]);
}
if (geoFeatureLayer != null)
{
geoFeatureLayer.Renderer = classBreaksRenderer as IFeatureRenderer;
}
}
三、UniqueValueRenderer专题图
是依据要素图层中的某个字段的不同值，给每个要素一个单独的颜色，以区分存在的每一个要素。
UniqueValueRenderer实现了IUniqueValueRenderer接口，提供了各种属性和方法，如AddValue方法用于将单个要素的某个字段值和与之相匹配的着色符号加入到UniqueValueRenderer对象。
/// <summary>
/// 单一值渲染（单字段）
/// </summary>
/// <param name="layerName">图层名</param>
/// <param name="RenderField">渲染字段</param>
/// <param name="FillStyle">填充样式</param>
/// <param name="valueCount">字段的唯一值个数</param>
public void createUniqueValueRander(string layerName, string RenderField, esriSimpleFillStyle FillStyle,int valueCount)
{
IGeoFeatureLayer geoFeatureLayer;
geoFeatureLayer = getGeoLayer(layerName);
IUniqueValueRenderer uniqueValueRenderer = new UniqueValueRendererClass();
//可以设置多个字段
uniqueValueRenderer.FieldCount = 1;//0-3个
uniqueValueRenderer.set_Field(0, RenderField);
//简单填充符号
ISimpleFillSymbol simpleFillSymbol = new SimpleFillSymbolClass();
simpleFillSymbol.Style = FillStyle;
IFeatureCursor featureCursor = geoFeatureLayer.FeatureClass.Search(null, false);
IFeature feature;
if (featureCursor != null)
{
IEnumColors enumColors = CreateAlgorithmicColorRamp(valueCount).Colors;
int fieldIndex = geoFeatureLayer.FeatureClass.Fields.FindField(RenderField);
for (int i = 0; i < valueCount; i++)
{
feature = featureCursor.NextFeature();
string nameValue = feature.get_Value(fieldIndex).ToString();
simpleFillSymbol = new SimpleFillSymbolClass();
simpleFillSymbol.Color = enumColors.Next();
uniqueValueRenderer.AddValue(nameValue, RenderField, simpleFillSymbol as ISymbol);
}
}
geoFeatureLayer.Renderer = uniqueValueRenderer as IFeatureRenderer;
}
/// <summary>
/// 单一值渲染(多字段）
/// </summary>
/// <param name="layerName">图层名</param>
/// <param name="RenderField">多字段名</param>
/// <param name="FillStyle">样式</param>
/// <param name="valueCount">每个字段中唯一值的个数</param>
public void createUniqueValueRander(string layerName, string[] RenderField, esriSimpleFillStyle FillStyle, int[] valueCount)
{
IGeoFeatureLayer geoFeatureLayer;
geoFeatureLayer = getGeoLayer(layerName);
IUniqueValueRenderer uniqueValueRenderer = new UniqueValueRendererClass();
//可以设置多个字段
uniqueValueRenderer.FieldCount = RenderField .Length;//0-3个
for (int i = 0; i < RenderField.Length; i++)
{
uniqueValueRenderer.set_Field(i, RenderField[i]);
}
//简单填充符号
ISimpleFillSymbol simpleFillSymbol = new SimpleFillSymbolClass();
simpleFillSymbol.Style = FillStyle;
IFeatureCursor featureCursor = geoFeatureLayer.FeatureClass.Search(null, false);
IFeature feature;
if (featureCursor != null)
{
for (int i = 0; i < RenderField.Length; i++)
{
IEnumColors enumColors = CreateAlgorithmicColorRamp(valueCount[i]).Colors;
int fieldIndex = geoFeatureLayer.FeatureClass.Fields.FindField(RenderField[i]);
for (int j = 0; j < valueCount[i]; j++)
{
feature = featureCursor.NextFeature();
string nameValue = feature.get_Value(fieldIndex).ToString();
simpleFillSymbol = new SimpleFillSymbolClass();
simpleFillSymbol.Color = enumColors.Next();
uniqueValueRenderer.AddValue(nameValue, RenderField[i], simpleFillSymbol as ISymbol);
}
}
}
geoFeatureLayer.Renderer = uniqueValueRenderer as IFeatureRenderer;
}
四、ProportionalSymbolRenderer专题图
使用梯度着色法制作的专题图。
ProportionalSymbolRenderer实现了IProportionalSymbolRenderer接口。
这种着色法需要用户知道最大和最小点各自代表的字段值、着色基于的字段和着色点使用的符号以及它在Legend要出现的级别数目。
/// <summary> /// 梯度着色 /// </summary> /// <param name="layerName">图层名字</param> /// <param name="ProportionField">要参考的字段</param> /// <param name="FillStyle">填充样式</param> /// <param name="fillColor">填充Color</param> /// <param name="characterMarkerSymbol">特征点符号</param> /// <param name="units">参考单位</param> /// <param name="pLegendSymbolCount">要分成的级数</param> public void createProportionSymbolRender(string layerName, string ProportionField, esriSimpleFillStyle FillStyle, IColor fillColor, ICharacterMarkerSymbol characterMarkerSymbol, esriUnits units, int pLegendSymbolCount) { IGeoFeatureLayer geoFeatureLayer; IFeatureLayer featureLayer; IProportionalSymbolRenderer proportionalSymbolRenderer; ITable table; ICursor cursor; IDataStatistics dataStatistics;//用一个字段生成统计数据 IStatisticsResults statisticsResult;//报告统计数据 //stdole.IFontDisp fontDisp;//定义字体 geoFeatureLayer = getGeoLayer(layerName); featureLayer = geoFeatureLayer as IFeatureLayer; table = geoFeatureLayer as ITable; cursor = table.Search(null, true); dataStatistics = new DataStatisticsClass(); dataStatistics.Cursor = cursor; dataStatistics.Field = ProportionField;//确定分级字段 statisticsResult = dataStatistics.Statistics; if (statisticsResult != null) { IFillSymbol fillSymbol = new SimpleFillSymbolClass(); fillSymbol.Color = fillColor; //ICharacterMarkerSymbol characterMarkerSymbol = new CharacterMarkerSymbolClass(); //fontDisp = new stdole.StdFontClass() as stdole.IFontDisp; //fontDisp.Name = "arial"; //fontDisp.Size = 20; //characterMarkerSymbol.Font = fontDisp; //characterMarkerSymbol.CharacterIndex = 90; //characterMarkerSymbol.Color = getRGB(255, 0, 0); //characterMarkerSymbol.Size = 8; proportionalSymbolRenderer = new ProportionalSymbolRendererClass(); proportionalSymbolRenderer.ValueUnit = units; proportionalSymbolRenderer.Field = ProportionField ; proportionalSymbolRenderer.FlanneryCompensation = false;//分级是不是在TOC中显示legend proportionalSymbolRenderer.MinDataValue = statisticsResult.Minimum; proportionalSymbolRenderer.MaxDataValue = statisticsResult.Maximum; proportionalSymbolRenderer.BackgroundSymbol = fillSymbol; proportionalSymbolRenderer.MinSymbol = characterMarkerSymbol as ISymbol; proportionalSymbolRenderer.LegendSymbolCount = pLegendSymbolCount;//要分成的级数 proportionalSymbolRenderer.CreateLegendSymbols(); geoFeatureLayer.Renderer = proportionalSymbolRenderer as IFeatureRenderer; } }