ArcGIS Engine专题地图渲染器的实现（入门版）

/// <summary>
/// 比例符号法渲染器(ProportionalSymbolRenderer)——用不同大小的符号绘制要素, 其大小对应某一字段值的比例。
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void 比例符号法渲染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;//声明要素图层
    IFeatureLayer pFtLayer;//声明专题图变量//在利用该方法进行着色时, 需获得最大和最小标识符号所代表的字段及其各个数值, 还需要确定每个字段数值所匹配的着色符号。
    IProportionalSymbolRenderer proportionalSymbolRenderer;//声明表格
    ITable table;//声明游标
    ICursor cursor;//用于统计变量
    IDataStatistics dataStatistics;//用于存放统计结果
    IStatisticsResults statisticsResults;//声明一个字体对象
    stdole.IFontDisp fontDisp;//获取图层geoFeatureLayer = getGeoLayer("北部湾");//强转为要素图层pFtLayer = geoFeatureLayer as IFeatureLayer;//图层类型转换成表table = geoFeatureLayer as ITable;//获取游标cursor = table.Search(null, true);//实例化数据统计对象dataStatistics = new DataStatisticsClass();//赋游标给数据统计对象的游标dataStatistics.Cursor = cursor;//获取图层要素中进行专题地图制图的字段名称, 此实例中所用的数据中字段名为"年"(2010年GDP增长速率)dataStatistics.Field = "年";//存放统计结果为统计对象的统计数据statisticsResults = dataStatistics.Statistics;//如果统计结果不为空if (statisticsResults != null){//简单填充符号IFillSymbol fillSymbol = new SimpleFillSymbolClass();//设置颜色fillSymbol.Color = getRGB(195, 255, 255);//设置简单线型符号ISimpleLineSymbol SLS = new SimpleLineSymbolClass();SLS.Color = getRGB(196, 196, 196);//颜色SLS.Width = 1.5;//宽度fillSymbol.Outline = SLS;//外边界线//利用ESRI特殊符号调用成员进行填充ICharacterMarkerSymbol characterMarkerSymbol = new CharacterMarkerSymbolClass();fontDisp = new stdole.StdFontClass() as stdole.IFontDisp;//调用指定子库(ESRI Default Marker是子库名称)fontDisp.Name = "ESRI Default Marker";//对characterMarkerSymbol的font属性characterMarkerSymbol.Font = fontDisp;//特征标记符号(Character Marker Symbol)的索引值//0xB6是C#特殊的16进制表示方法, 换算为十进制值182characterMarkerSymbol.CharacterIndex = 0xB6;//特征标记符号的颜色characterMarkerSymbol.Color = getRGB(253, 191, 110);//设计特征标记符号的尺寸characterMarkerSymbol.Size = 18;//实例化一个比例符号渲染器proportionalSymbolRenderer = new ProportionalSymbolRendererClass();proportionalSymbolRenderer.ValueUnit = esriUnits.esriUnknownUnits;//获取渲染字段proportionalSymbolRenderer.Field = "年";//是否启用颜色补偿(默认为否)proportionalSymbolRenderer.FlanneryCompensation = false;//赋值统计数据(比例符号渲染器)            //MinDataValue获取数据中最小值proportionalSymbolRenderer.MinDataValue = statisticsResults.Minimum;//获取数据中最大值proportionalSymbolRenderer.MaxDataValue = statisticsResults.Maximum;//在多边形特征上绘制比例标记符号时使用的背景填充符号proportionalSymbolRenderer.BackgroundSymbol = fillSymbol;//用于绘制具有规格化最小数据值的特征的符号。proportionalSymbolRenderer.MinSymbol = characterMarkerSymbol as ISymbol;//目录和图例中显示的符号数为3proportionalSymbolRenderer.LegendSymbolCount = 3;//创建图例, 设置完所有属性后调用。
        proportionalSymbolRenderer.CreateLegendSymbols();//赋值目标图层的渲染器属性geoFeatureLayer.Renderer = proportionalSymbolRenderer as IFeatureRenderer;}axMapControl1.Refresh(); //刷新axMapControl1axTOCControl1.Update(); //更新axTOCControl1

}

5、点状密度法渲染器

点状密度法渲染器(DotDensityRenderer)——在多边形特征中绘制不同密度的点
①制作点符号
②使用IDotDensityFillSymbo包装制作好的符号
③赋值点密度渲染(dotDensityRenderer)的点密度符号(DotDensitySymbol)属性
④赋值其它参数
⑤赋值目标图层的Renderer属性, 完成渲染
⑥刷新地图

/// <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axMapControl1axTOCControl1.Update(); //更新axTOCControl1

}

/// <summary>
/// 不填充颜色
/// </summary>
/// <returns></returns>
private IColor getNoRGB()
{IRgbColor pColor = new RgbColorClass();//.NullColor指示此颜色是否为空。true表明颜色为空pColor.NullColor = true;return pColor;//返回pColor
}