1工具效果展示：畫線，選擇與該線相交的要素並高亮顯示

2代碼實現

　　開發環境： c# 2010、 arcengine 10.1、　win7

　　思路：在mapcontrol中畫一條線（INewLineFeedback接口），並顯示；用map的SelectByShape方法選擇要素。

　　步驟：

　　a 在項目中添加BaseTool類，命名T_Tool.cs

　　b 在T_Tool中添加：INewLineFeedback m_displayFeedback = null 用於追蹤鼠標所畫的線段。

　　c 在OnMouseDown、OnMouseMove方法下面，實現畫線操作

　　d 在OnDblClick()下結束畫線，並顯示要素。

　　代碼：（OnMouseDown）

          pPoint = m_mapControl.ActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(X, Y);
          if (m_displayFeedback == null)
            {
                m_displayFeedback = new NewLineFeedbackClass();
                ISimpleLineSymbol pLine = m_displayFeedback.Symbol as ISimpleLineSymbol;
                RgbColorClass pColor=new RgbColorClass();
                pColor.Red=255;
                pColor.Green=0;
                pColor.Blue=0;
                pLine.Color = pColor;
                m_displayFeedback.Display = m_mapControl.ActiveView.ScreenDisplay;
                m_displayFeedback.Start(pPoint);
            }
            else
            {
                m_displayFeedback.AddPoint(pPoint);
            }        

　　在OnMouseMove下：

           pPoint = m_mapControl.ActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(X, Y);
           
            m_displayFeedback.MoveTo(pPoint);

　　在OnDblClick()　　　　　　　

　　　　　　　//雙擊的時候，結束畫線
　　　　　　IPolyline pLine = m_displayFeedback.Stop();            
　　　　　　//釋放m_displayFeedback
 

            m_displayFeedback = null;
            //顯示所畫圖形元素
            DrawGeometry(pLine as IGeometry);
            //選中高亮
            ISelectionEnvironment pSelectionEnvironment = new SelectionEnvironmentClass();
            m_mapControl.Map.SelectByShape(pLine as IGeometry, pSelectionEnvironment, false);
            m_mapControl.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeoSelection, null, null);
            
            //空間查詢
            ISpatialFilter pSpatialFilter = new SpatialFilterClass();
            pSpatialFilter.Geometry = pLine as IGeometry;
            pSpatialFilter.SpatialRel = esriSpatialRelEnum.esriSpatialRelIntersects;
            IFeatureLayer pFeatureLayer = m_mapControl.Map.get_Layer(0) as IFeatureLayer;
            IFeatureCursor pfeatureCursor= pFeatureLayer.Search(pSpatialFilter, false);
            IFeature pFeature = pfeatureCursor.NextFeature();
            while (pFeature != null)
            {
                //code goes here
                IFields pFields = pFeature.Fields;
                IField pField = null; 
                for (int i = 0; i < pFields.FieldCount; i++)
                {
　　　　　　　　　　//此處可以獲取要素類的字段名和每一個feature的字段值，還可以將數據存儲在Datatable中，
　　　　　　　　　　//方便與其他對象（gridtable等）進行聯動展示

                    pField= pFields.get_Field(i);
                    string filedName = pField.Name;
                    object fieldValue= pFeature.get_Value(i);
                    string field=fieldValue.ToString();
                }
                
                pFeature = pfeatureCursor.NextFeature();
            }

private void DrawGeometry(IGeometry geometry)
        {
            IGraphicsContainer pGraphicsContainer;
            IActiveView pActiveView;
            pGraphicsContainer = m_mapControl.ActiveView as IGraphicsContainer;
            pActiveView = m_mapControl.ActiveView;
            pGraphicsContainer.DeleteAllElements();
            if (geometry == null)
                return;
            try
            {
　　　　　　　　　　
                geometry.Project(m_mapControl.Map.SpatialReference);

                IElement m_element = new LineElementClass();
                m_element.Geometry = geometry;
                IRgbColor pColor;
                pColor = new RgbColorClass();
                pColor.Red = 200;
                pColor.Blue = 20;
                pColor.Green = 0;

                ILineSymbol pOutline;
                pOutline = new SimpleLineSymbolClass();
                pOutline.Width = 1.0;
                pOutline.Color = pColor;
                ISimpleLineSymbol pLineSymble = pOutline as ISimpleLineSymbol;
                pLineSymble.Style = esriSimpleLineStyle.esriSLSDot;


                ILineElement pFillshapeEle;
                pFillshapeEle = m_element as ILineElement;
                pFillshapeEle.Symbol = pOutline;
                m_element = pFillshapeEle as IElement;
                pGraphicsContainer.AddElement(m_element, 0);

                pActiveView.PartialRefresh(esriViewDrawPhase.esriViewGraphics, null, null);
            }
            catch (Exception err)
            {
　　　　　　　　　　//
            }

        }

　　e 工具的調用：

　　在系統菜單欄添加一個點擊按鈕，雙擊進入Click方法下，並用一下代碼調用剛剛實現的工具。

            T_Tool test = new  T_Tool();
            test.OnCreate(m_mapControl.Object);
            m_mapControl.CurrentTool = test;

c# AE實現欄選功能