ArcEngine简单教程——栅格、矢量图层的颜色渲染
ArcEngine简单教程汇总
目录
ArcEngine简单教程汇总
1 目的
2 概要
色带：
栅格渲染：
矢量渲染：
3代码
4小结
1 目的
实现简单的按照arcmap自带色带，进行图层渲染功能，包括
对栅格图层，按栅格值进行拉伸渲染、分级渲染、唯一值渲染
对矢量图层，按某一字段值进行分级渲染、唯一值渲染
2 概要
本文只介绍主要功能方法，具体的调用关系、窗口实现等完整完整demo可见：
https://download.csdn.net/download/nominior/12454058
色带：
1）获取
使用SymbologyControl控件获取ArcMap色带，色带位置：ArcMap安装路径/Styles/ESRI.Style
2）显示
使用C#中的combobox对色带进行显示（比SymbologyControl效果略好），分两个过程：
- 修改combobox的DrawItem方法，使得combobox可以绘制色带
- 遍历SymbologyControl中的色带，绘制到combobox中
栅格渲染：
- 包括拉伸渲染、分级渲染、唯一值渲染等渲染方式
- 基本渲染流程为：创建并设置对应渲染器，渲染颜色与渲染值映射，栅格图层渲
具体见 代码及注释
矢量渲染：
- 包括拉伸渲染、分级渲染、唯一值渲染等渲染方式
- 基本渲染流程为：创建并设置对应渲染器，数值处理，渲染颜色与渲染值映射，栅格图层渲染
具体见 代码及注释
3代码
涉及的ArcGIS引用、界面示意如图：
combobox色带显示代码
// combobox重绘
private void cb_colormap_DrawItem(object sender, DrawItemEventArgs e)
{
e.DrawBackground();
e.DrawFocusRectangle();
e.Graphics.DrawImage(cb_colormap.Items[e.Index] as Image, e.Bounds);
}
// 初始化符号库
private void InitSymbologyControl()
{
//色带定位
string sInstall = "D:\\ArcGIS\\Desktop10.2\\";
string defaultStyle = System.IO.Path.Combine(sInstall, "Styles\\ESRI.ServerStyle");
//色带读取
this.axSymbologyControl1.LoadStyleFile(defaultStyle);
this.axSymbologyControl1.StyleClass = esriSymbologyStyleClass.esriStyleClassColorRamps;
//色带另存
this.pSymbologyStyleClass = axSymbologyControl1.GetStyleClass(esriSymbologyStyleClass.esriStyleClassColorRamps);
}
// 初始化色带下拉框
private void InitColorRampCombobox()
{
this.cb_colormap.DrawMode = DrawMode.OwnerDrawFixed;
this.cb_colormap.DropDownStyle = ComboBoxStyle.DropDownList;
//绘制色带
for (int i = 0; i < pSymbologyStyleClass.ItemCount; i++)
{
//从另存中读取色带
IStyleGalleryItem pStyleGalleryItem = pSymbologyStyleClass.GetItem(i);
IPictureDisp pPictureDisp = pSymbologyStyleClass.PreviewItem(pStyleGalleryItem, cb_colormap.Width, cb_colormap.Height);
Image image = Image.FromHbitmap(new IntPtr(pPictureDisp.Handle));
cb_colormap.Items.Add(image);
}
cb_colormap.SelectedIndex = 25;
}栅格渲染代码
#region 不同方式的栅格渲染
private void SetRasterSymbol(IRasterLayer pRasterLayer)
{
//获取cb选择的色带序号，根据序号选择色带
int symbol_index = cb_colormap.SelectedIndex;
ISymbologyStyleClass symbologyStyleClass = axSymbologyControl1.GetStyleClass(esriSymbologyStyleClass.esriStyleClassColorRamps);
IStyleGalleryItem mStyleGalleryItem = symbologyStyleClass.GetItem(symbol_index);
IColorRamp colorramp_select = (IColorRamp)mStyleGalleryItem.Item;
if (cb_method.Text == "Stretch")
{
RasterStretchRender(colorramp_select, pRasterLayer);
}
else if (cb_method.Text == "Classify")
{
if (textBox1.Text == "不分")
{
}
else
{
int cls_num = Convert.ToInt32(textBox1.Text);
RasterClassifyRender(colorramp_select, pRasterLayer, cls_num);
}
}
else if (cb_method.Text == "Unique")
{
RasterUniqueRender(colorramp_select, pRasterLayer);
}
//视图刷新
map.ActiveView.ContentsChanged();
map.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeography, null, null);
}
private void RasterStretchRender(IColorRamp pColorRamp, IRasterLayer pRasterLayer)
{
//渲染器定义
IRasterStretchColorRampRenderer pSRRender = new RasterStretchColorRampRendererClass();
IRasterRenderer pRRender = pSRRender as IRasterRenderer;
//渲染器设置
pRRender.Raster = pRasterLayer.Raster;
pRRender.Update();
pSRRender.ColorRamp = pColorRamp;
//栅格渲染
pRasterLayer.Renderer = pRRender;
}
private void RasterClassifyRender(IColorRamp pColorRamp, IRasterLayer pRasterLayer, int cls_num)
{
//渲染器定义
IRasterClassifyColorRampRenderer pRCRender = new RasterClassifyColorRampRendererClass();
IRasterRenderer pRRend = pRCRender as IRasterRenderer;
//渲染器设置
pRRend.Raster = pRasterLayer.Raster;
pRRend.Update();
pRCRender.ClassCount = cls_num;
//渲染映射
int gap = pColorRamp.Size / (cls_num-1);
IFillSymbol fillSymbol = new SimpleFillSymbol() as IFillSymbol;
for (int i = 0; i < pRCRender.ClassCount; i++)
{
int index;
if (i < pRCRender.ClassCount - 1)
{
index = i * gap;
}
else
{
index = pColorRamp.Size-1;
}
fillSymbol.Color = pColorRamp.get_Color(index);
pRCRender.set_Symbol(i, fillSymbol as ISymbol);
pRCRender.set_Label(i, pRCRender.get_Break(i).ToString("0.00") +"-"+ pRCRender.get_Break(i+1).ToString("0.00"));
}
//栅格渲染
pRasterLayer.Renderer = pRRend;
}
private void RasterUniqueRender(IColorRamp pColorRamp, IRasterLayer pRasterLayer)
{
//渲染器定义
IRasterUniqueValueRenderer pRURender = new RasterUniqueValueRendererClass();
IRasterRenderer pRRend = pRURender as IRasterRenderer;
//渲染器设置
pRRend.Raster = pRasterLayer.Raster;
pRRend.Update();
IUniqueValues uniqueValues = new UniqueValuesClass();
IRasterCalcUniqueValues calcUniqueValues = new RasterCalcUniqueValuesClass();
calcUniqueValues.AddFromRaster(pRasterLayer.Raster, 0, uniqueValues);//计算第0通道的唯一值
//渲染映射
int gap = pColorRamp.Size / (uniqueValues.Count - 1);
IFillSymbol fillSymbol = new SimpleFillSymbol() as IFillSymbol;
for (int i = 0; i < uniqueValues.Count; i++)
{
int index;
if (i < uniqueValues.Count - 1)
{
index = i * gap;
}
else
{
index = pColorRamp.Size - 1;
}
fillSymbol.Color = pColorRamp.get_Color(index);
pRURender.AddValue(0, i, uniqueValues.get_UniqueValue(i));
pRURender.set_Label(0, i, uniqueValues.get_UniqueValue(i).ToString());
pRURender.set_Symbol(0, i, fillSymbol as ISymbol);
}
//栅格渲染
pRasterLayer.Renderer = pRRend;
}
#endregion矢量渲染代码
#region 不同方式的矢量渲染
private void SetFeatureSymbol(IFeatureLayer pFeatureLayer)
{
//获取cb选择的色带序号，根据序号选择色带
int symbol_index = cb_colormap.SelectedIndex;
ISymbologyStyleClass symbologyStyleClass = axSymbologyControl1.GetStyleClass(esriSymbologyStyleClass.esriStyleClassColorRamps);
IStyleGalleryItem mStyleGalleryItem = symbologyStyleClass.GetItem(symbol_index);
IColorRamp colorramp_select = (IColorRamp)mStyleGalleryItem.Item;
if (cb_method.Text == "Classify")
{
if (textBox1.Text == "不分")
{
}
else
{
int cls_num = Convert.ToInt32(textBox1.Text);
FeatureClassifyRender(colorramp_select, pFeatureLayer, cls_num);
}
}
else if (cb_method.Text == "Unique")
{
FeatureUniqueRender(colorramp_select, pFeatureLayer);
}
//视图刷新
map.ActiveView.ContentsChanged();
map.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeography, null, null);
}
private void FeatureClassifyRender(IColorRamp pColorRamp, IFeatureLayer pFeatureLayer, int cls_num)
{
if (pField.Type == esriFieldType.esriFieldTypeDouble || pField.Type == esriFieldType.esriFieldTypeInteger || pField.Type == esriFieldType.esriFieldTypeOID)
{
//渲染器定义
IClassBreaksRenderer pFCRender = new ClassBreaksRendererClass();
IFeatureRenderer pFRender = pFCRender as IFeatureRenderer;
//渲染器设置
pFCRender.Field = pField.Name;
pFCRender.BreakCount = cls_num+1;
//数值处理
ITableHistogram histo = new BasicTableHistogramClass();//获取直方图
histo.Field = pField.Name;
histo.Table = pFeatureLayer.FeatureClass as ITable;
object dbArray, nArray;//定义分级数组
(histo as IBasicHistogram).GetHistogram(out dbArray, out nArray);
double[] dataArray = dbArray as double[];
int[] fredArray = nArray as int[];
IClassifyGEN classify = new EqualIntervalClass();//平均分级法
classify.Classify(dataArray, fredArray, cls_num);
double[] Breaks = classify.ClassBreaks as double[];//分级数组确定
//渲染映射
pFCRender.MinimumBreak = Breaks[0];
int gap = pColorRamp.Size / (pFCRender.BreakCount - 1);
for (int i = 0; i < cls_num; i++)
{
int index;
if (i < cls_num - 1)
{
index = i * gap;
}
else
{
index = pColorRamp.Size - 1;
}
ISymbol pSymbol = null;
if (pFeatureLayer.FeatureClass.ShapeType == esriGeometryType.esriGeometryPolygon)
{
pSymbol = new SimpleFillSymbolClass();
(pSymbol as IFillSymbol).Outline.Width = 1.0;
(pSymbol as IFillSymbol).Color = pColorRamp.get_Color(index);
}
else if (pFeatureLayer.FeatureClass.ShapeType == esriGeometryType.esriGeometryPolyline)
{
pSymbol = new SimpleLineSymbolClass();
(pSymbol as ILineSymbol).Width = 1.0;
(pSymbol as ILineSymbol).Color = pColorRamp.get_Color(index);
}
else if (pFeatureLayer.FeatureClass.ShapeType == esriGeometryType.esriGeometryPoint)
{
pSymbol = new SimpleMarkerSymbolClass();
(pSymbol as IMarkerSymbol).Size = 1.0;
(pSymbol as IMarkerSymbol).Color = pColorRamp.get_Color(index);
}
pFCRender.set_Break(i, Breaks[i + 1]);
pFCRender.set_Symbol(i, pSymbol);
pFCRender.set_Label(i, Breaks[i].ToString() + "-" + Breaks[i + 1].ToString());
}
//矢量图层渲染
(pFeatureLayer as IGeoFeatureLayer).Renderer = pFRender;
}
}
private void FeatureUniqueRender(IColorRamp pColorRamp, IFeatureLayer pFeatureLayer)
{
//渲染器定义
IUniqueValueRenderer pFURender = new UniqueValueRendererClass();
IFeatureRenderer pFRender = pFURender as IFeatureRenderer;
//渲染器设置
pFURender.FieldCount = 1;
pFURender.set_Field(0, pField.Name);
if (pField.Type == esriFieldType.esriFieldTypeString)
{
pFURender.set_FieldType(0, true);
}
else
{
pFURender.set_FieldType(0, false);
}
//数值处理
IFeatureClass pFeatureClass = pFeatureLayer.FeatureClass;
IFeatureCursor lFeatureCursor = pFeatureClass.Search(null, false);
IDataStatistics pData = new DataStatisticsClass();
pData.Field = pField.Name;
pData.Cursor = lFeatureCursor as ICursor;
IEnumerator pEnumVar = pData.UniqueValues;
string[] uniqueValues = new string[pData.UniqueValueCount];
pEnumVar.Reset();
int n = 0;
while (pEnumVar.MoveNext())
{
uniqueValues[n++] = pEnumVar.Current.ToString();
}
//渲染映射
int gap = pColorRamp.Size / (uniqueValues.Length - 1);
for (int i = 0; i < uniqueValues.Length; i++)
{
int index;
if (i < uniqueValues.Length - 1)
{
index = i * gap;
}
else
{
index = pColorRamp.Size - 1;
}
ISymbol pSymbol = null;
if (pFeatureLayer.FeatureClass.ShapeType == esriGeometryType.esriGeometryPolygon)
{
pSymbol = new SimpleFillSymbolClass();
(pSymbol as IFillSymbol).Outline.Width = 1.0;
(pSymbol as IFillSymbol).Color = pColorRamp.get_Color(index);
}
else if (pFeatureLayer.FeatureClass.ShapeType == esriGeometryType.esriGeometryPolyline)
{
pSymbol = new SimpleLineSymbolClass();
(pSymbol as ILineSymbol).Width = 1.0;
(pSymbol as ILineSymbol).Color = pColorRamp.get_Color(index);
}
else if (pFeatureLayer.FeatureClass.ShapeType == esriGeometryType.esriGeometryPoint)
{
pSymbol = new SimpleMarkerSymbolClass();
(pSymbol as IMarkerSymbol).Size = 2.0;
(pSymbol as IMarkerSymbol).Color = pColorRamp.get_Color(index);
}
pFURender.AddValue(uniqueValues[i], "", pSymbol);
}
//矢量图层渲染
(pFeatureLayer as IGeoFeatureLayer).Renderer = pFRender;
}
#endregion4小结
渲染过程2个关键对象：色带、渲染器，1个重要过程渲染器与对应渲染值、渲染颜色的关系映射