获取数据表中某字段唯一值

using ESRI.ArcGIS.Geodatabase;
using System.Collections;
using ESRI.ArcGIS.Carto;
 函数代码：
        /// 

        /// 得到要素类某字段的唯一值
       /// 
       /// 要素类
       /// 指定要得到唯一值的字段
       /// 唯一值字符数据
        public static List GetUniqueValue(IFeatureClass pFeatureClass, string strFld)
        {
           //得到IFeatureCursor游标
           IFeatureCursor pCursor = pFeatureClass.Search(null, false);           
           //coClass对象实例生成
           IDataStatistics pData=new DataStatisticsClass();
           pData.Field=strFld;
           pData.Cursor=pCursor as ICursor;
           //枚举唯一值
           IEnumerator pEnumVar=pData.UniqueValues ;
           //可记录总条数：int RecordCount=pData.UniqueValueCount;
           //定义List泛型           
           List plist = new List();
           pEnumVar.Reset();
           while(pEnumVar.MoveNext())
           {
               plist.Add(pEnumVar.Current.ToString());
           }       
           return plist;
       }
事件代码：
       private void Form1_Load(object sender, EventArgs e)
       {
           ILayer player = axMapControl1.get_Layer(0);
           IFeatureLayer pfeatureLayer = player as IFeatureLayer;
           IFeatureClass pfeatureClass = pfeatureLayer.FeatureClass;
           GetUniqueValue(pfeatureClass, "省名");
       }