符号化之Renderer( 渲染)体系
ArcGIS Engine9.3对GIS数据的符号化分为矢量数据渲染和栅格数据渲染两大类。接下来分别介绍FeatureRender和RasterRender。
1.FeatureRender对象
FeatureRenderer是一个抽象类，它有15个子类负责进行不同类型的着色运算。它们都实现了IFeatureRenderer接口，这个接口定义了进行要素图层符号化的公共属性和方法。
可以通过IGeoFeatureLayer::Renderer属性获得一个要素图层的符号化对象
表四
| 要素符号化类型 | 描述 |
| SimpleRender | 简单符号化 |
| UniqueValueRender | 唯一值符号化 |
| BiUniqueValueRender | 双变量唯一值符号化 |
| ChartRender | 图表符号化 |
| ClassBreaksRenderer | 分类等级符号化 |
| DotDensityRenderer | 点密度符号化 |
| ProportionalSymbolRenderer | 根据属性值设置符号大小进行符号化 |
| ScaleDependentRenderer | 依比例尺符号化 |
| RepresentationRenderer | 制图表达符号化 |
| CoTrackSymbologyRenderer(TrackingAnalyst) | 轨迹符号化（应用于TrackingAnaylyst扩展模块） |
| EnhancedInfoRenderder(TrackingAnalyst) | 增强信息符号化（应用于TrackingAnaylyst扩展模块） |
| UniqueValueTextRenderer(TrackingAnalyst) | 唯一值文本符号化（应用于TrackingAnaylyst扩展模块） |
| NAStopRenderer(NetworkAnalyst) | 停止符号化(应用于网络分析扩展模块) |
| FeatureVertexRenderer(SurveyExt) | 要素定点符号化(应用于测量分析扩展模块) |
| SharedEdgeRenderer(EditorExt) | 用于绘制拓扑元素 |
常用的要素符号化类型主要有以下6种类型，如图13所示：
图13
由于篇幅有限不再对每一种符号化类型的使用进行讲解，在后边的实例中将为读者演示如何进行唯一值符号化。
2.RasterRender对象
RasterRender是一个抽象类，它有15个子类负责进行不同类型的着色运算。它们都实现了IRasterRender接口，这个接口定义了栅格图层符号化的公共属性和方法。可以通过IRasterLayer::Renderer属性获得一个栅格图层的符号化对象。
| 要素符号化类型 | 描述 |
| RasterRGBRenderer | 栅格RGB符号化 |
| RasterUniqueValueRenderer | 唯一值符号化 |
| RasterColormapRenderer | 双变量唯一值符号化 |
| RasterClassifyColorRampRenderer | 图表符号化 |
| RasterStretchColorRampRenderer | 分类等级符号化 |
| RasterDiscreteColorRenderer | 点密度 符号化 |
栅格符号化类型结构图如图14所示：
图14
以下代码片段是对一个RasterLayer进行RasterStretchColorRampRenderer符号化操作：
///
/// StretchColorRamp符号化RasterLayer
///
///RasterLayer
publicvoid SetStretchColorRampRenderer(IRasterLayer pRasterLayer)
{
try
{
//创建RasterStretchColorRampRendererClass对象
IRasterStretchColorRampRenderer pRStretchRender=newRasterStretchColorRampRendererClass();
//QI到IRasterRenderer
IRasterRenderer pRasterRender=pRStretchRenderas IRasterRenderer;
pRasterRender.Raster = pRasterLayer asIRaster;
pRasterRender.Update();
//创建两个起始颜色
IRgbColor pFromRgbColor =new RgbColorClass();
pFromRgbColor.Red = 255;
IRgbColor pToRgbColor =new RgbColorClass();
pToRgbColor.Blue = 255;
//创建起止颜色带
IAlgorithmicColorRamp pAlgorithmicColorRamp =newAlgorithmicColorRampClass();
pAlgorithmicColorRamp.Size = 255;
pAlgorithmicColorRamp.FromColor = pFromRgbColor asIColor;
pAlgorithmicColorRamp.ToColor = pToRgbColor asIColor;
bool btrue=true;
pAlgorithmicColorRamp.CreateRamp(out btrue);
//选择拉伸颜色带符号化的波段
pRStretchRender.BandIndex = 0;
//设置拉伸颜色带符号化所采用的颜色带
pRStretchRender.ColorRamp = pAlgorithmicColorRamp asIColorRamp;
pRasterRender.Update();
//符号化RasterLayer
pRasterLayer.Renderer = pRasterRender;
}
catch(Exception Err)
{
MessageBox.Show(Err.Message,"提示",MessageBoxButtons.OK,MessageBoxIcon.Information);
}
}
AE之分级颜色专题图渲染
参考代码1：
private void 分级渲染ToolStripMenuItem_Click(object sender, EventArgs e)
{
//值分级
IBasicHistogram pBasicHis = new BasicTableHistogramClass();
ITableHistogram pTabHis = (ITableHistogram)pBasicHis;
pTabHis.Field = "w1";
ITable pTab = (ITable)axMapControl1.get_Layer(0);
pTabHis.Table = pTab;
object doubleArrVal, longArrFreq;
pBasicHis.GetHistogram(out doubleArrVal, out longArrFreq);
IClassifyGEN pClassify = new EqualIntervalClass(); //NaturalBreaksClass
int nDes = 5;
pClassify.Classify(doubleArrVal, longArrFreq, ref nDes);
object classes = pClassify.ClassBreaks;
System.Array pArr = (System.Array)classes;
//算法梯度颜色
IAlgorithmicColorRamp pAlgoColorRamp = new AlgorithmicColorRampClass();
pAlgoColorRamp.Size = pArr.Length;
IRgbColor pFromColor = new RgbColorClass(), pToColor = new RgbColorClass();
pFromColor.Red = 0;
pFromColor.Green = 255;
pFromColor.Blue = 0;
pToColor.Red = 255;
pToColor.Green = 0;
pToColor.Blue = 255;
pAlgoColorRamp.FromColor = pFromColor;
pAlgoColorRamp.ToColor = pToColor;
bool ok = true;
pAlgoColorRamp.CreateRamp(out ok);
//颜色梯度结束
IClassBreaksRenderer pRender = new ClassBreaksRendererClass();
pRender.BreakCount = pArr.Length;
pRender.Field = "w1";
ISimpleFillSymbol pSym;
for (int i = 0; i < pArr.Length; i++)
{
pRender.set_Break(i, (double)pArr.GetValue(i));
pSym = new SimpleFillSymbolClass();
pSym.Color = pAlgoColorRamp.get_Color(i);
pRender.set_Symbol(i, (ISymbol)pSym);
}
IGeoFeatureLayer pGeoLyr = (IGeoFeatureLayer)axMapControl1.get_Layer(0);
pGeoLyr.Renderer = (IFeatureRenderer)pRender;
axMapControl1.Refresh();
axTOCControl1.Update();
}
参考代码2：
private void 分层设色ToolStripMenuItem_Click(object sender, EventArgs e)
{
//获取当前图层 ，并把它设置成IGeoFeatureLayer的实例
IMap pMap = axMapControl1.Map;
ILayer pLayer = pMap.get_Layer(0) as IFeatureLayer;
IFeatureLayer pFeatureLayer = pLayer as IFeatureLayer;
IGeoFeatureLayer pGeoFeatureLayer = pLayer as IGeoFeatureLayer;
//获取图层上的feature
IFeatureClass pFeatureClass = pFeatureLayer.FeatureClass;
IFeatureCursor pFeatureCursor = pFeatureClass.Search(null, false);
IFeature pFeature = pFeatureCursor.NextFeature();
//
IFeatureRenderer PR=pGeoFeatureLayer.Renderer;
//JoinData("县级区域", "DZGB", "sectioncode"); //join外部表
// int DC ;
int desiredClasses = 5;
string fieldName = "w1";
int classesCount;
double[] classes;
string strOutput = "";
bool ok;
object dataFrequency;
object dataValues;
ITable pTable ;
//IClassify pClassify;
EqualIntervalClass pClassify;
//IBasicHistogram pTableHistogram = new BasicTableHistogramClass();
//IHistogram pTableHistogram = new BasicTableHistogramClass();
ITableHistogram pTableHistogram = new BasicTableHistogramClass() as ITableHistogram;
IBasicHistogram pHistogram;
IClassBreaksRenderer pClassBreaksRenderer;
IHsvColor pFromColor;
IHsvColor pToColor;
IAlgorithmicColorRamp pAlgorithmicColorRamp;
IEnumColors pEnumColors;
IColor pColor;
ISimpleFillSymbol pSimpleFillSymbol;
pLayer = (IFeatureLayer)axMapControl1.get_Layer(0);
pGeoFeatureLayer = (IGeoFeatureLayer)pLayer;
pTable = (ITable)pGeoFeatureLayer;
pHistogram = (IBasicHistogram)pTableHistogram;
// Get values and frequencies for the field
pTableHistogram.Field = fieldName;
pTableHistogram.Table = pTable;
pHistogram.GetHistogram(out dataValues, out dataFrequency);
// Put values and frequencies into an Equal Interval Classify Object
pClassify = new EqualIntervalClass();
//pClassify = new NaturalBreaksClass();
pClassify.SetHistogramData(dataValues, dataFrequency);
pClassify.Classify(dataValues, dataFrequency, ref desiredClasses);
//pClassify.Classify(ref desiredClasses);
classes = (double[])pClassify.ClassBreaks;
classesCount = classes.Length;
// Initialise a new Class Breaks renderer
// Supply the number of Class Breaks and the field to perform. the class breaks on
pClassBreaksRenderer = new ClassBreaksRendererClass();
pClassBreaksRenderer.Field = fieldName;
pClassBreaksRenderer.BreakCount = classesCount;
pClassBreaksRenderer.SortClassesAscending = true;
// Use algorithmic color ramp to generate an range of colors between YELLOW to RED
// Initial color: YELLOW
pFromColor = new HsvColorClass();
pFromColor.Hue = 60;
pFromColor.Saturation = 100;
pFromColor.Value = 96;
// Final color: RED
pToColor = new HsvColorClass();
pToColor.Hue = 0;
pToColor.Saturation = 100;
pToColor.Value = 96;
// Set up HSV Color ramp to span from YELLOW to RED
pAlgorithmicColorRamp = new AlgorithmicColorRampClass();
pAlgorithmicColorRamp.Algorithm = esriColorRampAlgorithm.esriHSVAlgorithm;
pAlgorithmicColorRamp.FromColor = pFromColor;
pAlgorithmicColorRamp.ToColor = pToColor;
pAlgorithmicColorRamp.Size = classesCount;
pAlgorithmicColorRamp.CreateRamp(out ok);
pEnumColors = pAlgorithmicColorRamp.Colors;
for (int index = 0; index < classesCount - 1; index++)
{
pColor = pEnumColors.Next();
pSimpleFillSymbol = new SimpleFillSymbolClass();
pSimpleFillSymbol.Color = pColor;
pSimpleFillSymbol.Style = esriSimpleFillStyle.esriSFSSolid;
pClassBreaksRenderer.set_Symbol(index, (ISymbol)pSimpleFillSymbol);
pClassBreaksRenderer.set_Break(index, classes[index + 1]);
// Store each break value for user output
strOutput += "-" + classes[index + 1] + " ";
}
pGeoFeatureLayer.Renderer = (IFeatureRenderer)pClassBreaksRenderer;
//this.axMapControl1.Refresh();
/////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////////////
//get the custom property from which is supposed to be the layer to be saved
object customProperty = null;
//IMapControl3 mapControl = null;
customProperty = axMapControl1.CustomProperty;
//ask the user to set a name for the new layer file
SaveFileDialog saveFileDialog = new SaveFileDialog();
saveFileDialog.Filter = "Layer File|*.lyr|All Files|*.*";
saveFileDialog.Title = "生成专题图";
saveFileDialog.RestoreDirectory = true;
saveFileDialog.FileName = System.IO.Path.Combine(saveFileDialog.InitialDirectory, pGeoFeatureLayer.Name + ".lyr");
//get the layer name from the user
DialogResult dr = saveFileDialog.ShowDialog();
if (saveFileDialog.FileName != "" && dr == DialogResult.OK)
{
if (System.IO.File.Exists(saveFileDialog.FileName))
{
//try to delete the existing file
System.IO.File.Delete(saveFileDialog.FileName);
}
//create a new LayerFile instance
ILayerFile layerFile = new LayerFileClass();
//create a new layer file
layerFile.New(saveFileDialog.FileName);
//attach the layer file with the actual layer
layerFile.ReplaceContents((ILayer)pGeoFeatureLayer);
//save the layer file
layerFile.Save();
//ask the user whether he'd like to add the layer to the map
if (DialogResult.Yes == MessageBox.Show("Would you like to add the layer to the map?", "Message", MessageBoxButtons.YesNo,MessageBoxIcon.Question))
{
axMapControl1.AddLayerFromFile(saveFileDialog.FileName, 0);
}
}
IActiveView pActiveView = axMapControl1.Map as IActiveView;
pActiveView.Refresh();
axTOCControl1.Update();
}
参考代码3：
private void 等级专题图ToolStripMenuItem_Click(object sender, EventArgs e)
{
// 获取当前图层，并把它设置成IGeoFeatureLayer的实例
ILayer pLayer = axMapControl1.get_Layer(0);
IFeatureLayer pFeatLayer = (IFeatureLayer)pLayer;
IGeoFeatureLayer pGeoFeatLayer = (IGeoFeatureLayer)pLayer;
IFeatureClass pFeatClass = pFeatLayer.FeatureClass;
// We're going to retrieve frequency data from a population
// field and then clasify this data
ITable pTable = (ITable)pFeatClass;
IBasicHistogram pBasicHistogram = new BasicTableHistogramClass();
ITableHistogram pTableHistogram = (ITableHistogram)pBasicHistogram;
// Get values and frequencies for the population field into a table histogram object
string fieldName = "w1";
pTableHistogram.Field = fieldName;
pTableHistogram.Table = pTable;
object dataValues;
object dataFrequency;
pBasicHistogram.GetHistogram(out dataValues, out dataFrequency);
IClassifyGEN pClassifyGEN = new QuantileClass();
int numClass = 3;
pClassifyGEN.Classify(dataValues, dataFrequency, ref numClass);
double[] classes = (double[])pClassifyGEN.ClassBreaks;
long classesCount = long.Parse(classes.GetUpperBound(0).ToString());
// Initialize a new class breaks renderer and supply the number of class breaks
// and the field to perform the class breaks on
IClassBreaksRenderer pClassBreaksRenderer = new ClassBreaksRendererClass();
pClassBreaksRenderer.Field = fieldName;
pClassBreaksRenderer.MinimumBreak = classes[0];
pClassBreaksRenderer.SortClassesAscending = true;
// 设置着色对象的分级数目
pClassBreaksRenderer.BreakCount = int.Parse(classesCount.ToString());
// 创建并设置随机色谱
IAlgorithmicColorRamp pAlgorithmicColorRamp = new AlgorithmicColorRampClass();
pAlgorithmicColorRamp.Algorithm = esriColorRampAlgorithm.esriCIELabAlgorithm;
IEnumColors pEnumColors;
IRgbColor pColor1 = new RgbColorClass();
IRgbColor pColor2 = new RgbColorClass();
pColor1.Red = 255;
pColor1.Green = 210;
pColor1.Blue = 210;
pColor2.Red = 190;
pColor2.Green = 0;
pColor2.Blue = 170;
pAlgorithmicColorRamp.FromColor = pColor1;
pAlgorithmicColorRamp.ToColor = pColor2;
pAlgorithmicColorRamp.Size = numClass;
bool ok = true;
pAlgorithmicColorRamp.CreateRamp(out ok);
pEnumColors = pAlgorithmicColorRamp.Colors;
pEnumColors.Reset();
IClassBreaksUIProperties pUIProperties = (IClassBreaksUIProperties)pClassBreaksRenderer;
pUIProperties.ColorRamp = "Custom";
ISimpleFillSymbol pSimpleMarkerSymbol = new SimpleFillSymbolClass();
IColor pColor;
int[] colors = new int[numClass];
// be careful, indices are different for the different lists
for (int breakIndex = 0; breakIndex < classesCount; breakIndex++)
{
pClassBreaksRenderer.set_Label(breakIndex, classes[breakIndex] + "-" + classes[breakIndex + 1]);
pUIProperties.set_LowBreak(breakIndex, classes[breakIndex]);
ISimpleFillSymbol pFillSymbol = new SimpleFillSymbolClass();
pColor = pEnumColors.Next();
pFillSymbol.Color = pColor;
colors[breakIndex] = pColor.RGB;
pClassBreaksRenderer.set_Symbol(breakIndex, (ISymbol)pFillSymbol);
pClassBreaksRenderer.set_Break(breakIndex, classes[breakIndex + 1]);
}
// 将等级图渲染对象与渲染图层挂钩
pGeoFeatLayer.Renderer = (IFeatureRenderer)pClassBreaksRenderer;
axMapControl1.ActiveView.Refresh();
axTOCControl1.Update();
}
参考代码4：
private void 等级图ToolStripMenuItem_Click(object sender, EventArgs e)
{
//获取当前图层 ，并把它设置成IGeoFeatureLayer的实例
IMap pMap = axMapControl1.Map;
ILayer pLayer = pMap.get_Layer(0) as IFeatureLayer;
IFeatureLayer pFeatureLayer = pLayer as IFeatureLayer;
IGeoFeatureLayer pGeoFeatureLayer = pLayer as IGeoFeatureLayer;
//获取图层上的feature
IFeatureClass pFeatureClass = pFeatureLayer.FeatureClass;
IFeatureCursor pFeatureCursor = pFeatureClass.Search(null, false);
IFeature pFeature = pFeatureCursor.NextFeature();
//////////////////////////////////////////////////////////////////////
//定义所需的接口对象和相关变量
IClassBreaksUIProperties pUIProperties;
object dataValues;
object dataFrequency;
//double[] cb;
int breakIndex;
long ClassesCount;
int numClass;
numClass = 10;
double[] Classes;
//////////////////////////////////////////////////////////////////////
ITable pTable;
pTable = pFeatureClass as ITable;
IBasicHistogram pBasicHist = new BasicTableHistogramClass();
ITableHistogram pTableHist;
pTableHist = (ITableHistogram)pBasicHist;
//Get values and frequencies for the population field into a table histogram object
pTableHist.Field = "w1";
pTableHist.Table = pTable;
pBasicHist.GetHistogram(out dataValues, out dataFrequency);
IClassifyGEN pClassifyGEN = new QuantileClass();
pClassifyGEN.Classify(dataValues, dataFrequency, ref numClass);
Classes = (double[])pClassifyGEN.ClassBreaks;
ClassesCount = long.Parse(Classes.GetUpperBound(0).ToString());
//Initialise a new class breaks renderer and supply the number of class breaks and the field to perform. the class breaks on.
IClassBreaksRenderer pClassBreaksRenderer = new ClassBreaksRendererClass();
pClassBreaksRenderer.Field = "w1";
//pClassBreaksRenderer.BreakCount = ClassesCount;
pClassBreaksRenderer.MinimumBreak = Classes[0];
pClassBreaksRenderer.SortClassesAscending = true;
//设置着色对象的分级数目
pClassBreaksRenderer.BreakCount = int.Parse(ClassesCount.ToString());
//创建并设置随机色谱
IAlgorithmicColorRamp pColorRamp = new AlgorithmicColorRampClass();
pColorRamp.Algorithm = esriColorRampAlgorithm.esriCIELabAlgorithm;
IEnumColors pEnumColors;
IRgbColor pColor1 = new RgbColorClass();
IRgbColor pColor2 = new RgbColorClass();
pColor1.Red = 255;
pColor1.Green = 210;
pColor1.Blue = 210;
pColor2.Red = 190;
pColor2.Green = 0;
pColor2.Blue = 170;
pColorRamp.FromColor = pColor1;
pColorRamp.ToColor = pColor2;
pColorRamp.Size = numClass;
bool ok = true;
//pColorRamp.CreateRamp(out ok);
pColorRamp.CreateRamp(out ok);
pEnumColors = pColorRamp.Colors;
pEnumColors.Reset();// use this interface to set dialog properties
pUIProperties = pClassBreaksRenderer as IClassBreaksUIProperties;
pUIProperties.ColorRamp = "Custom";
ISimpleFillSymbol pSimpleMarkerSymbol = new SimpleFillSymbolClass();
IColor pColor;
int[] colors = new int[numClass];
// be careful, indices are different for the diff lists
for (breakIndex = 0; breakIndex < ClassesCount; breakIndex++)
{
pClassBreaksRenderer.set_Label(breakIndex, Classes[breakIndex] + " - " + Classes[breakIndex + 1]);
pUIProperties.set_LowBreak(breakIndex, Classes[breakIndex]);
pSimpleMarkerSymbol = new SimpleFillSymbolClass();
pColor = pEnumColors.Next();
pSimpleMarkerSymbol.Color = pColor;
colors[breakIndex] = pColor.RGB;
pClassBreaksRenderer.set_Symbol(breakIndex, (ISymbol)pSimpleMarkerSymbol);
pClassBreaksRenderer.set_Break(breakIndex, Classes[breakIndex + 1]);
}
//将等级图渲染对象与渲染图层挂钩
pGeoFeatureLayer.Renderer = (IFeatureRenderer)pClassBreaksRenderer;
//刷新地图和TOOCotrol
IActiveView pActiveView = axMapControl1.Map as IActiveView;
pActiveView.Refresh();
axTOCControl1.Update();
}
from: http://blog.sina.com.cn/s/blog_90b91bf101015jkj.html
http://blog.sina.com.cn/s/blog_642c66ed0101cs5m.html