Arcgis Server+Asp.net(C#)的唯一值渲染

#region "唯一值渲染"
/// <summary> 唯一值渲染:uvRenderer () </summary>
/// <Author>Cavalry</Author>
/// <param name="pFieldName">渲染的字段名</param>
/// <DateTime>2008-09-02 10:59</DateTime>
public static void uvRenderer(string pFieldName)
{
  string servername = ConfigurationManager.AppSettings["MapHostName"];
    //地图服务器的计算机名
  string mapserverobject = ConfigurationManager.AppSettings["MapServiceName"];
    //地图服务名称(ArcCatalog中服务的名称)
  ESRI.ArcGIS.ADF.Connection.AGS.AGSServerConnection agsconnection = new
    ESRI.ArcGIS.ADF.Connection.AGS.AGSServerConnection();
  agsconnection.Host = servername;
  agsconnection.Connect();
  IServerObjectManager som = agsconnection.ServerObjectManager;
  IServerContext serverContext = som.CreateServerContext(mapserverobject,
    "MapServer");

  IMapServer mapServer = serverContext.ServerObject as IMapServer;
  IMapServerInfo mapInfo = mapServer.GetServerInfo(mapServer.DefaultMapName);
  IMapDescription mapDesc = mapInfo.DefaultMapDescription;
  IMapServerObjects mapServerObjects = mapServer as IMapServerObjects;

  ILayer layer = mapServerObjects.get_Layer(mapServer.DefaultMapName, 0);
    //获取面图层
  IFeatureLayer pFLayer = layer as IFeatureLayer;
  IGeoFeatureLayer geoLayer = layer as IGeoFeatureLayer;

  IFeatureClass pFeatCls = geoLayer.FeatureClass as IFeatureClass;
  //查询条件
  IQueryFilter pQueryFilter = serverContext.CreateObject(
    "esriGeodatabase.QueryFilter")as IQueryFilter;
  IFeatureCursor pFeatCursor = pFeatCls.Search(pQueryFilter, false);
  //设置一个随机颜色范围
  IRandomColorRamp rx = serverContext.CreateObject(
    "esriDisplay.RandomColorRamp")as IRandomColorRamp;
  rx.MinSaturation = 20;
  rx.MaxSaturation = 40;
  rx.MinValue = 85;
  rx.MaxValue = 100;
  rx.StartHue = 76;
  rx.EndHue = 188;
  rx.Size = 360;
  rx.UseSeed = true;
  rx.Seed = 43;
  //此处需要用CreateObject方有权限对IGeoLayer的Render属性进行设置(被这个问题困扰了N久)！！！
  IUniqueValueRenderer pRender = (IUniqueValueRenderer)
    serverContext.CreateObject("esriCarto.UniqueValueRenderer");
  Int32 n;
  //同样需要CreateObject方法
  ISimpleFillSymbol symd = serverContext.CreateObject(
    "esriDisplay.SimpleFillSymbol")as ISimpleFillSymbol;
  symd.Style = ESRI.ArcGIS.Display.esriSimpleFillStyle.esriSFSSolid;
  pRender.FieldCount = 1;
  pRender.set_Field(0, pFieldName);
  pRender.DefaultSymbol = symd as ISymbol;
  pRender.UseDefaultSymbol = true;

  IFeature pFeat = pFeatCursor.NextFeature();
  n = pFeatCls.FeatureCount(pQueryFilter); //n为查询到的图元的数量
  int i = 0;
  bool ValFound;
  int uh, iField;
  IFields pFields = pFeatCursor.Fields;
  iField = pFields.FindField(pFieldName); //获得要分析的字段的索引值

  while (i < n)
  {
    ISimpleFillSymbol symx = serverContext.CreateObject(
      "esriDisplay.SimpleFillSymbol")as ISimpleFillSymbol;
    symx.Style = ESRI.ArcGIS.Display.esriSimpleFillStyle.esriSFSSolid;
    symx.Outline.Width = 1;
    string x = pFeat.get_Value(iField).ToString();
    ValFound = false;
    //先查询pRender之前是否已有添加过该值，有的话则不再添加
    for (uh = 0; uh < pRender.ValueCount; uh++)
    {
      if (pRender.get_Value(uh) == x)
      {
        ValFound = true;
        break;
      }
    }
    //如果该值为尚未添加进pRender，则将值和符号样式添加给pRender
    if (!ValFound)
    {
      pRender.AddValue(x, pFieldName, (ISymbol)symx);
      pRender.set_Label(x, x);
      pRender.set_Symbol(x, (ISymbol)symx);
    }
    pFeat = pFeatCursor.NextFeature();
    i++;
  }
  //得到pRender里含有多少个不同的值，将其赋给rx的Size属性
  rx.Size = pRender.ValueCount;
  bool ok;
  rx.CreateRamp(out ok);
  Int32 ny;
  IEnumColors RColors = rx.Colors;
  RColors.Reset();
  //为每个不同的值设置不同的颜色
  for (ny = 0; ny < pRender.ValueCount; ny++)
  {
    string xv = pRender.get_Value(ny);
    if (xv != "")
    {
      ISimpleFillSymbol jsy = pRender.get_Symbol(xv)as ISimpleFillSymbol;
      jsy.Color = RColors.Next();
      pRender.set_Symbol(xv, (ISymbol)jsy);
    }
  }
  pRender.ColorScheme = "Custom";
  pRender.set_FieldType(0, true);

  geoLayer.Renderer = (IFeatureRenderer)pRender;
  geoLayer.DisplayField = pFieldName;
}

#endregion
}

}