Arcgis Server的唯一值渲染

这段代码是根据别人的代码，稍加了修改。

#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>

public void uvRenderer(string pFieldName)
{
        string servername = "ZHOUWEN";
    //地图服务器的计算机名
    string mapserverobject = "DCM2";
      //地图服务名称(ArcCatalog中服务的名称)

   //上面两个自己看着改就行。
    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, 10);//10为图层序号，自己可以改
    //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 = 0;
    rx.MaxSaturation = 100;
    rx.MinValue = 0;
    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
     iField = 11;//需要渲染字段的id

    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;

    }

自己加一个按钮，调用以上函数，就可以实现唯一值渲染了。不过颜色配置可能有点不太好。自己改一下。