ArcGIS Engine开发教程之图层符号化（五）：利用ESRI自带符号库进行唯一值符号化

利用ESRI自带的符号库进行唯一值符号化一图层开发实例
        学会开发唯一值符号化要素图层功能

图172.步骤

１.准备点数据，添加属性字段“类别”;
２.并为要素“类别”属性值分别设置为“Hospital2”,“School 1”,“Airport”三种属性值。
３.实现唯一值符号化功能
４.运行程序实现效果
3.功能开发

实现唯一值符号化功能代码如下：

///<summary> ///获取符号库中符号 ///</summary> ///<param name="sServerStylePath">符号库全路径名称</param> ///<param name="sGalleryClassName">GalleryClass名称</param> ///<param name="symbolName">符号名称</param> ///<returns>符号</returns>privateISymbol GetSymbol(string sServerStylePath,string sGalleryClassName, string symbolName)
{

try {

//ServerStyleGallery对象 IStyleGallery pStyleGaller =new ServerStyleGalleryClass(); IStyleGalleryStorage pStyleGalleryStorage = pStyleGalleras IStyleGalleryStorage; IEnumStyleGalleryItem pEnumSyleGalleryItem=null; IStyleGalleryItem pStyleGallerItem =null; IStyleGalleryClass pStyleGalleryClass =null; //使用IStyleGalleryStorage接口的AddFile方法加载ServerStyle文件 pStyleGalleryStorage.AddFile(sServerStylePath); //遍历ServerGallery中的Class for(int i = 0; i < pStyleGaller.ClassCount; i++) { pStyleGalleryClass = pStyleGaller.get_Class(i); if(pStyleGalleryClass.Name != sGalleryClassName) continue; //获取EnumStyleGalleryItem对象 pEnumSyleGalleryItem = pStyleGaller.get_Items(sGalleryClassName, sServerStylePath,""); pEnumSyleGalleryItem.Reset(); //遍历pEnumSyleGalleryItem pStyleGallerItem = pEnumSyleGalleryItem.Next(); while(pStyleGallerItem !=null) {

if(pStyleGallerItem.Name == symbolName) { //获取符号 ISymbol pSymbol = pStyleGallerItem.Item asISymbol; System.Runtime.InteropServices.Marshal.ReleaseComObject(pEnumSyleGalleryItem); System.Runtime.InteropServices.Marshal.ReleaseComObject(pStyleGalleryClass); return pSymbol; }

pStyleGallerItem = pEnumSyleGalleryItem.Next(); } } System.Runtime.InteropServices.Marshal.ReleaseComObject(pEnumSyleGalleryItem); System.Runtime.InteropServices.Marshal.ReleaseComObject(pStyleGalleryClass); return null;

}

catch (Exception Err) {

MessageBox.Show(Err.Message, "提示",MessageBoxButtons.OK,MessageBoxIcon.Information); returnnull;

}

}

///<summary>

///设置要素图层唯一值符号化

///</summary>

///<param name="pFeatureLayer"></param>

privatevoid UniqueValueRenderFlyr(IFeatureLayer pFeatureLayer)

{

   try

   {

       //创建UniqueValueRendererClass对象

IUniqueValueRenderer pUVRender =new UniqueValueRendererClass();

List<string> pFieldValues=new List<string>();

pFieldValues.Add("Hospital 2");
pFieldValues.Add("School 1");
pFieldValues.Add("Airport");

for(int i=0;i<pFieldValues.Count;i++)
{

ISymbol pSymbol=new SimpleMarkerSymbolClass();
pSymbol =GetSymbol(@"C:\Program Files\ArcGIS\Styles\ESRI.ServerStyle","MarkerSymbols",pFieldValues【i】);

//添加唯一值符号化字段值和相对应的符号
pUVRender.AddValue(pFieldValues,pFieldValues,pSymbol);

}

//设置唯一值符号化的字段个数和字段名
pUVRender.FieldCount = 1;

pUVRender.set_Field(0,"类别");

IGeoFeatureLayer pGFeatureLyr = pFeatureLayeras IGeoFeatureLayer;

//设置IGeofeatureLayer的Renderer属性
pGFeatureLyr.Renderer = pUVRender asIFeatureRenderer;
   }

   catch (Exception Err)
    {

MessageBox.Show(Err.Message,"提示",MessageBoxButtons.OK,MessageBoxIcon.Information);
    }
}
privatevoid button1_Click(object sender,EventArgs e)
{

   IFeatureLayer pFeatureLayer =this.axMapControl1.get_Layer(0)as IFeatureLayer;

   UniqueValueRenderFlyr(pFeatureLayer);

   this.axMapControl1.Refresh();

}

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