用移动的element选择Features

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using ESRI.ArcGIS.DataSourcesGDB;
using ESRI.ArcGIS.esriSystem;
using ESRI.ArcGIS.Geodatabase;
using ESRI.ArcGIS.Carto;
using ESRI.ArcGIS.Geometry;
using ESRI.ArcGIS.Display;

namespace WindowsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            IPropertySet pPS = new PropertySetClass();
            IWorkspaceFactory pWF = new SdeWorkspaceFactoryClass();
            pPS.SetProperty("Server","8B63691CDAE4488");
            pPS.SetProperty("Instance", "5159");
            pPS.SetProperty("Database", "TestElementEdit");
            pPS.SetProperty("User", "sde");
            pPS.SetProperty("Password", "zhangjun1130");
            pPS.SetProperty("Version", "sde.default");
            IWorkspace pWs = pWF.Open(pPS, 0);
            IFeatureWorkspace pFWs=pWs as IFeatureWorkspace;


            IFeatureClass pFC = pFWs.OpenFeatureClass("ElementEdit");
            IFeatureLayer pFL = new FeatureLayerClass();
            pFL.FeatureClass = pFC;

            axMapControl1.AddLayer(pFL);


        }

        private void axMapControl1_OnMouseDown(object sender, ESRI.ArcGIS.Controls.IMapControlEvents2_OnMouseDownEvent e)
        {

            if (radioButton3.Checked == true)
            {
                IPolygon pPolygon = (IPolygon)axMapControl1.TrackPolygon();
                IGraphicsContainer pGC = (IGraphicsContainer)axMapControl1.Map;
                IActiveView pActiver = (IActiveView)axMapControl1.Map;
                IPolygonElement pPolygonElement = new PolygonElementClass();
                IElement pElement = (IElement)pPolygonElement;
                IElementEditVertices pElementEditVertices = (IElementEditVertices)pPolygonElement;
                pElement.Geometry = pPolygon;
                pGC.AddElement(pElement, 0);
                pActiver.Refresh();
            pElementEditVertices.MovingVertices = true;
            //ISelectionTracker pST=null;
            //pElementEditVertices.GetMoveVerticesSelectionTracker();
            }

        }

        private void axMapControl1_OnMouseUp(object sender, ESRI.ArcGIS.Controls.IMapControlEvents2_OnMouseUpEvent e)
        {
            if (radioButton1.Checked == true)
            {
                IGraphicsContainer pGC = (IGraphicsContainer)axMapControl1.Map;
                IGraphicsContainerSelect pGCS = (IGraphicsContainerSelect)pGC;
                IEnumElement pEE = pGCS.SelectedElements;
                IElement pE = pEE.Next();
                IElementEditVertices pEEV = pE as IElementEditVertices;
                pEEV.MovingVertices = true;
                ISpatialFilter pSF = new SpatialFilterClass();
                pSF.GeometryField = "Shape";
                pSF.Geometry = pE.Geometry;
                pSF.SpatialRel = esriSpatialRelEnum.esriSpatialRelIntersects;

                IFeatureSelection pFS = axMapControl1.Map.get_Layer(0) as IFeatureSelection;
                pFS.SelectFeatures(pSF, esriSelectionResultEnum.esriSelectionResultNew, false);
                (axMapControl1.Map as IActiveView).Refresh();
               
                ISelection pS = axMapControl1.Map.FeatureSelection;
                IEnumFeature pEF = (IEnumFeature)pS;
                int i = 0;
                IFeature pF = pEF.Next();
                while (pF!= null)
                {
                    i++;
                    pF=pEF.Next();
                }
                MessageBox.Show(i.ToString());


            }
        }
    }
}