ArcEngine+C# 实现 Identify 功能及缓冲区查询

        private void axMapControl1_OnMouseDown(object sender, ESRI.ArcGIS.MapControl.IMapControlEvents2_OnMouseDownEvent e)
        {            
if(this.blnIsIdentifyEnable)
            {
                //如果查询比较频繁，此类变量可以设置成类级别
                IFeatureLayer pFL;
                IFeatureSelection pFeatureSelection;
                IEnvelope pEnv;
                IGeometry pGeometry;
                ISpatialFilter pSpatialFilter;
                ISelectionSet pSelectionSet;
                IEnumIDs pEnumIDs;
                IFeature pFeature;
//                ImageList imageList = new ImageList();
//                imageList.

                //用于查询的矩形（相当于点的缓冲区，这样比生成缓冲区节省资源），
                //envelope的大小根据实际情况设定，以方便使用为准
                pEnv = new EnvelopeClass();
                pEnv.PutCoords(e.mapX-200,e.mapY-200,e.mapX+200,e.mapY+200);
                pGeometry = pEnv as IGeometry;
                pSpatialFilter = new SpatialFilterClass();
                pSpatialFilter.Geometry = pGeometry;
                pSpatialFilter.SpatialRel = esriSpatialRelEnum.esriSpatialRelIntersects;

                //运用singleton模式设计窗体，只允许存在一个ShowAttributeTable实例
                ShowAttributeTable frmShowAttribute = ShowAttributeTable.CreateForm();
                frmShowAttribute.Show();
                frmShowAttribute.AttributeTreeView.Nodes.Clear();//首先清除上次结果
                frmShowAttribute.AttributeTreeView.ShowLines = true;

                frmShowAttribute.AttributeTreeView.ShowPlusMinus = true;
                
                TreeNode rootNode = new TreeNode();
                rootNode.Text = "属性信息";
//                rootNode.ImageIndex

                Font font = new Font("黑体",10);
                rootNode.NodeFont = font;
                //添加根节点“属性信息”
                frmShowAttribute.AttributeTreeView.Nodes.Add(rootNode);


                //没有必要将地图上的高亮选择清除，因为下面对每个图层的选择都用esriSelectionResultNew，会自动清除上次的高亮显示，
                //而不同图层之间的高亮选择不会有任何影响，因为IFeatureSelection接口的一切属性和方法都是针对一个图层
//                this.axMapControl1.Map.ClearSelection();
                for(int i=0;i<this.axMapControl1.LayerCount;i++)
                {
                    pFL = this.axMapControl1.get_Layer(i) as IFeatureLayer;
                    if(pFL.Visible && pFL.Selectable)
                    {
                        pFeatureSelection = pFL as IFeatureSelection;
                        //选择之前先清除，这是个好习惯（除非是用Add方式）
                        pFeatureSelection.Clear();
                        pFeatureSelection.SelectFeatures(pSpatialFilter,esriSelectionResultEnum.esriSelectionResultNew,true);
                        pSelectionSet = pFeatureSelection.SelectionSet;
                        //如果选择集内有Feature
                        if(pSelectionSet.Count>0)
                        {
                            //构建图层节点并添加到根节点
                            TreeNode layerNameNode = new TreeNode();