static void Main()
    {
        PointStruct ps1 = new PointStruct();
        ps1.x = ps1.y = 22;

        PointStruct ps2 = new PointStruct();
        ps2.x = ps2.y = 33;

        ps1 = ps2;
        ps2.x = ps2.y = 55;

        Console.WriteLine("ps1 is ({0}, {1})", ps1.x, ps1.y);
        Console.WriteLine("ps2 is ({0}, {1})", ps2.x, ps2.y);
        Console.WriteLine("ps1.Equals(ps2) results in " + ps1.Equals(ps2));

        PointClass pc1 = new PointClass();
        pc1.x = pc1.y = 22;

        PointClass pc2 = new PointClass();
        pc2.x = pc2.y = 33;

        pc1 = pc2;
        pc2.x = pc2.y = 55;

        Console.WriteLine("pc1 is ({0}, {1})", pc1.x, pc1.y);
        Console.WriteLine("pc2 is ({0}, {1})", pc2.x, pc2.y);
        Console.WriteLine("pc1.Equals(pc2) results in " + pc1.Equals(pc2));
        Console.WriteLine("pc1 == pc2 results in " + (pc1 == pc2));
    }

        protected override void OnMouseDown(ESRI.ArcGIS.Desktop.AddIns.Tool.MouseEventArgs arg)
        {
            int intx = arg.X;
            int inty = arg.Y;
            IPoint pPoints = new PointClass();
            pPoints.PutCoords(intx, inty);

            IActiveView activeView = ArcMap.Document.ActiveView;
            pPoints = activeView.ScreenDisplay.DisplayTransformation.ToMapPoint(-100, 40);//x,y为屏幕坐标

            ESRI.ArcGIS.Display.IScreenDisplay screenDisplay = activeView.ScreenDisplay;
            ESRI.ArcGIS.Display.IDisplayTransformation displayTransformation = screenDisplay.DisplayTransformation;
            pPoints=displayTransformation.ToMapPoint(-120, 40);

            IMxDocument doc = ArcMap.Document;
            IMap map = doc.FocusMap;
            pPoints=doc.ActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(-100, 40);

            AlterForm frm = null;
            if (frm == null || frm.IsDisposed)
                frm = new AlterForm(intx,inty);

            frm.Show();
            frm.TopMost = true;
            frm.Width = 400;
            frm.Height = 300;
            frm.Left = 500;
        }

        private void axPageLayoutControl1_OnDoubleClick(object sender, ESRI.ArcGIS.Controls.IPageLayoutControlEvents_OnDoubleClickEvent e)
        {
            if (e.button == 1)
            {
                //标注的修改
                if (axPageLayoutControl1.CurrentTool == null) return;
                if (((axPageLayoutControl1.CurrentTool) as ICommand).Name == "ControlToolsGraphicElement_SelectTool")
                {
                    IPoint pPoint = new PointClass();
                    pPoint.PutCoords(e.pageX, e.pageY);

                    IGraphicsContainer pGraphicsContainer = axPageLayoutControl1.PageLayout as IGraphicsContainer;

                    IEnumElement pEnumElement = pGraphicsContainer.LocateElements(pPoint, 10);
                    if (pEnumElement != null)
                    {
                        IElement pElement = pEnumElement.Next();
                        if (pElement is ITextElement)
                        {
                            ITextElement ptextElement = pElement as ITextElement;
                            MapPrint.TextSetUp textSetUp = new MapPrint.TextSetUp();
                            textSetUp.UpdateTextElement(ptextElement);
                            textSetUp.Show();
                        }
                    }

                }
            }
        }

        /// <summary>
        /// 将字符串格式转化为Geometry
        /// </summary>
        /// <param name="geom">    客户端传递多边形格式 1) x1,y1;x2,y2;x3,y3.......xn,yn;x1,y1;保证起始闭合 为无环
        ///                                            2) x1,y1,flag3;x2,y2,flag3;x3,y3,flag3.......xn,yn,,flagn;
        /// </param>
        /// <returns></returns>
        public static IPolygon BuildPolygon(string geom)
        {
            if (string.IsNullOrEmpty(geom) == true)
            {
                throw new Exception(sErroCoordinatesIsNull);
            }

            string[] points = geom.Split(new char[] { ';' }, StringSplitOptions.RemoveEmptyEntries);
            if (points != null && points.Length > 2)
            {
                int pointCount = points.Length;
                IPolygon polygon = null;
                IPoint point = null;
                object missing = Type.Missing;
                IGeometryCollection pGeoColl = new PolygonClass() as IGeometryCollection;
                IPointCollection pPointCol = new RingClass();
                for (int i = 0; i < pointCount; i++)
                {
                    string[] pts = points[i].Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
                    point = new PointClass();
                    double x = 0.0;
                    double y = 0.0;
                    int flag = 0;
                    bool bX = double.TryParse(pts[0], out x);
                    bool bY = double.TryParse(pts[1], out y);
                    bool bFlag = int.TryParse(pts[2], out flag);
                    if (bX && bY && bFlag)
                    {
                        pPointCol.AddPoint(point, ref  missing, ref missing);
                        if (flag == -1 || i == (pointCount - 1))
                        {
                            pGeoColl.AddGeometry(pPointCol as IRing, ref missing, ref missing);
                            pPointCol = null;
                            break;
                        }
                        else if (flag == -2)
                        {
                            pGeoColl.AddGeometry(pPointCol as IRing, ref missing, ref missing);
                            pPointCol = new RingClass();
                            continue;
                        }
                    }
                    else
                    {
                        throw new Exception(sErroCoordinatesValueIllegal);
                    }
                }
                if (pPointCol.PointCount > 0)
                {
                    pGeoColl.AddGeometry(pPointCol as IRing, ref missing, ref missing);
                }
                polygon = pGeoColl as IPolygon;
                SimplifyGeometry(polygon);
                return polygon;
            }
            else
            {
                throw new Exception(sErroCoordinatesValueIllegal);
            }
        }

        /// <summary>
        /// 绘制推断断层
        /// </summary>
        /// <params name="title"></params>
        /// <params name="faultagePointList"></params>
        /// <params name="bId"></params>
        /// <returns></returns>
        public static bool DrawTddc(String title, List<InferFaultagePoint> faultagePointList, String bId)
        {
            List<IPoint> listptS = new List<IPoint>();
            List<IPoint> listptX = new List<IPoint>();

            foreach (var i in faultagePointList)
            {
                if (i.up_or_down == "上盘")
                {
                    IPoint point = new PointClass();
                    point.X = i.coordinate_x;
                    point.Y = i.coordinate_y;
                    point.Z = i.coordinate_z;

                    listptS.Add(point);
                }
                else if (i.up_or_down == "下盘")
                {
                    IPoint point = new PointClass();
                    point.X = i.coordinate_x;
                    point.Y = i.coordinate_y;
                    point.Z = i.coordinate_z;

                    listptX.Add(point);
                }
            }

            return DrawTDDC(title, bId, listptS, listptX);
        }

        protected override void OnClick()
        {
            IActiveView activeView = ArcMap.Document.ActiveView;
            
            IMap map = activeView as IMap;
            ILayer layer = map.get_Layer(0);
            IFeatureLayer featureLayer = layer as IFeatureLayer;
            IFeatureClass featureClass = featureLayer.FeatureClass;

            IPoint point = new PointClass();
            point.PutCoords(-117.1, 34.075); //(LONG, LAT)

            IWorkspace workspace = GetWorkspace();
            IWorkspaceEdit workspaceEdit = workspace as IWorkspaceEdit;

            workspaceEdit.StartEditing(true);
            workspaceEdit.StartEditOperation();

            // -------------- Perform your editing tests here ------------------
            CreateFeature(featureClass, point);     
            //UpdateFeature(featureClass);
            //DeleteFeature(featureClass);

            // -----------------------------------------------------------------

            workspaceEdit.StopEditOperation();
            workspaceEdit.StopEditing(true);

            ArcMap.Application.CurrentTool = null;
        }

        public Form1()
        {
            if (!ESRI.ArcGIS.RuntimeManager.Bind(ESRI.ArcGIS.ProductCode.ArcReader))
            {
                if (!ESRI.ArcGIS.RuntimeManager.Bind(ESRI.ArcGIS.ProductCode.EngineOrDesktop))
                {
                    MessageBox.Show("Unable to bind to ArcGIS runtime. Application will be shut down.");
                    return;
                }
            }
            InitializeComponent();

            //IMap.ClipGeometry Property;

            string filePath = @"E:\Downloads\ARCgis\United States\USA Base Map.mxd";
            if (axMapControl1.CheckMxFile(filePath))
                axMapControl1.LoadMxFile(filePath, Type.Missing, Type.Missing);
            IPoint point = new PointClass();
            point.X = -100;
            point.Y = 40000;

            System.Drawing.Point p = new System.Drawing.Point(101, 37);

               // axMapControl1.CenterAt(point);
            //IEnvelope pEnvelope = this.axMapControl1.Extent;
            axMapControl1.PointToClient(p);
            //pEnvelope.CenterAt(point);
            //this.axMapControl1.Extent = pEnvelope;

            //axMapControl1.ActiveView.ScreenDisplay.RotateMoveTo(point);
            ////Draw the rotated display.
            //axMapControl1.ActiveView.ScreenDisplay.RotateTimer();

            axMapControl1.Refresh();
        }

		public SimplePointCursor(string filePath, IFields fields, int OID, 
			System.Array fieldMap, IEnvelope queryEnv, esriGeometryType geomType)	
		{
			//HIGHLIGHT: 0 - Set up cursor
			m_bIsFinished = false;
			m_pStreamReader = new System.IO.StreamReader(filePath);
			m_fields = fields;
			m_iOID = OID;
			m_fieldMap = fieldMap;
			m_searchEnv = queryEnv;
			switch (geomType)
			{
				case esriGeometryType.esriGeometryPolygon:
					m_wkGeom = new Polygon() as IGeometry;
					m_workPts = new PointClass[5];
					for (int i = 0; i < m_workPts.Length; i++)
						m_workPts[i] = new PointClass();
					break;
				case esriGeometryType.esriGeometryPolyline:
					m_wkGeom = new PolylineClass() as IGeometry;
					m_workPts = new PointClass[5];
					for (int i = 0; i < m_workPts.Length; i++)
						m_workPts[i] = new PointClass();
					break;
				
				case esriGeometryType.esriGeometryPoint:
					m_wkGeom = new PointClass() as IGeometry;
					break;
				default:	//doesn't need to set worker geometry if it is table 
					break;
			}

			//advance cursor so data is readily available
			this.NextRecord();
		}

        private void cmdOK_Click(object sender, EventArgs e)
        {
            //calc distance between points
              double dbp = 0;
              if (rbNOP.Checked)
            dbp = m_polyline.Length / (int.Parse(txtNOP.Text) + 1);
              else
            dbp = int.Parse(txtDist.Text);

              m_editor.StartOperation();
              this.Cursor = Cursors.WaitCursor;

              //create points at distance between points up to total length
              for (double d = dbp; d < m_polyline.Length; d += dbp)
              {
            IConstructPoint contructionPoint = new PointClass();
            contructionPoint.ConstructAlong(m_polyline, esriSegmentExtension.esriNoExtension,d,false);
            CreatePoint(contructionPoint as IPoint);
              }

              //create points at start and end of sketch
              if (chkEnds.Checked)
              {
            CreatePoint(m_polyline.FromPoint);
            CreatePoint(m_polyline.ToPoint);
               }

              this.Cursor = Cursors.Default;
              m_editor.StopOperation(A4LGSharedFunctions.Localizer.GetString("CrtPtsAlongLine"));
              this.Close();
        }

        public void getGlobeCoodinates(AxGlobeControl axGlobeControl, int x, int y, out double X, out double Y, out double Z)
        {
            //string coordInfo = "坐标信息";
            try
            {
                //获取点击坐标的X、Y
                IPoint globePoint = new PointClass();
                IGlobeDisplay globeDisplay = axGlobeControl.GlobeDisplay;
                ISceneViewer sceneViewer = globeDisplay.ActiveViewer;
                System.Object owner = System.Type.Missing;
                System.Object object1 = System.Type.Missing;
                globeDisplay.Locate(sceneViewer, x, y, false, false, out globePoint, out owner, out object1);

                //coordInfo = globePoint.X.ToString("F8") + "," + globePoint.Y.ToString("F8") + "," + globePoint.Z.ToString("F4");
                X = globePoint.X;
                Y = globePoint.Y;
                Z = globePoint.Z;
                //return coordInfo;
            }
            catch
            {
                X = 0;
                Y = 0;
                Z = 0;
                //return coordInfo;
            }
        }

        public static IPoint ConstructPoint2D(double x, double y)
        {
            IPoint point = new PointClass();
            point.X = x;
            point.Y = y;

            return point;
        }

 /// <summary>
 /// 坐标系转换-----投影坐标系转WGS84
 /// </summary>
 /// <param name="x">x坐标</param>
 /// <param name="y">y坐标</param>
 /// <returns>转换后的IPoint</returns>
 public static IPoint getGeoPoint(double x, double y)
 {
     IPoint pProjPoint = new PointClass();
     pProjPoint.PutCoords(x, y);
     ISpatialReferenceFactory pSRF = new SpatialReferenceEnvironmentClass();
     pProjPoint.SpatialReference = pSRF.CreateProjectedCoordinateSystem((int)(esriSRProjCSType.esriSRProjCS_WGS1984UTM_31N));
     pProjPoint.Project(pSRF.CreateGeographicCoordinateSystem((int)(esriSRGeoCSType.esriSRGeoCS_WGS1984)));
     return pProjPoint;      //此时为经纬度点
 }

        public static IPoint GeographicToTile(double lon, double lat, int zoom)
        {
            // From http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames#C.23

            IPoint point = new PointClass();
            point.X = (float)((lon + 180.0) / 360.0 * (1 << zoom));
            point.Y = (float)((1.0 - Math.Log(Math.Tan(lat * Math.PI / 180.0) + 1.0 / Math.Cos(lat * Math.PI / 180.0)) / Math.PI) / 2.0 * (1 << zoom));

            return point;
        }

        /// <summary>
        /// Returns NW corner of the tile
        /// </summary>
        /// <param name="tile_x"></param>
        /// <param name="tile_y"></param>
        /// <param name="zoom"></param>
        /// <returns></returns>
        public static IPoint TileToWorldPos(long tile_x, long tile_y, long zoom)
        {
            IPoint p = new PointClass();
            double n = Math.PI - ((2.0 * Math.PI * tile_y) / Math.Pow(2.0, zoom));

            p.X = (float)((tile_x / Math.Pow(2.0, zoom) * 360.0) - 180.0);
            p.Y = (float)(180.0 / Math.PI * Math.Atan(Math.Sinh(n)));

            return p;
        }

        public static IPoint TileToGeographic(int tileX, int tileY, int zoom)
        {
            // From http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames#C.23

            IPoint point = new PointClass();
            double n = Math.PI - ((2.0 * Math.PI * tileY) / Math.Pow(2.0, zoom));
            point.X = (float)((tileX / Math.Pow(2.0, zoom) * 360.0) - 180.0);
            point.Y = (float)(180.0 / Math.PI * Math.Atan(Math.Sinh(n)));
            return point;
        }

        internal void AddPPGeocodedPoint(double lat, double lng)
        {
            // Set the coordinate system of the data frame.
            ArcMap.Document.ActiveView.FocusMap.SpatialReference = DefineGCS(); 
            ArcMap.Document.ActiveView.Refresh();

            IPoint iPoint = new PointClass();
            // Set the coordinate system of your point to match your data frame
            iPoint.SpatialReference = DefineGCS();
            iPoint.X = lng;
            iPoint.Y = lat;

            IMap map = ArcMap.Document.ActiveView as IMap;
            IGraphicsContainer graphicsContainer = (IGraphicsContainer)map; // Explicit Cast
            IElement element = null;

            // set the point color
            IColor pointColor = new RgbColor();
            //pointColor.RGB = 255255255;
            pointColor.RGB = 255000000;

            // Marker symbols
            ESRI.ArcGIS.Display.ISimpleMarkerSymbol simpleMarkerSymbol = new SimpleMarkerSymbolClass();
            simpleMarkerSymbol.Color = pointColor;
            simpleMarkerSymbol.Outline = true;
            simpleMarkerSymbol.OutlineColor = pointColor;
            simpleMarkerSymbol.Size = 10;
            simpleMarkerSymbol.Style = esriSimpleMarkerStyle.esriSMSCircle;

            // Marker element
            IMarkerElement markerElement = new MarkerElementClass();
            markerElement.Symbol = simpleMarkerSymbol;
            markerElement.Symbol.Color = pointColor;

            element = (IElement)markerElement; // Explicit Cast

            // set the element name
            IElementProperties3 elemProperties = element as IElementProperties3;
            elemProperties.Name = string.Concat(lng, " ,", lat);
            elemProperties.AnchorPoint = esriAnchorPointEnum.esriCenterPoint;

            // Add the element to a graphics container and refresh the ActiveView
            if (!(element == null))
            {
                element.Geometry = iPoint;
                graphicsContainer.AddElement(element, 0);
                IEnvelope envelope = new EnvelopeClass();
                envelope = ArcMap.Document.ActiveView.Extent;
                envelope.CenterAt(iPoint);
                //ArcMap.Document.ActiveView.Extent = envelope;
                //map.MapScale = 2400;
                map.MapScale = 5000;
                ArcMap.Document.ActiveView.Refresh();
            }
        }

 static Button1()
 {
     IPoint p1 = null;
     for (int i = 0; i < pntlst.Count - 1; ++i)
     {
         p1 = new PointClass();
         p1.X = pntlst[i];
         p1.Y = pntlst[i + 1];
         pntclassList.Add(p1);
     }
 }

        private void toolStripButton1_Click(object sender, EventArgs e)
        {
            IEnvelope pEnvelope = new EnvelopeClass();
            IPoint pPoint = new PointClass();
            pPoint.PutCoords(Convert.ToDouble(txtlong.Text), Convert.ToDouble(txtlat.Text));

            pEnvelope = pAxMapControl.Extent;
            pEnvelope.CenterAt(pPoint);
            pAxMapControl.Extent = pEnvelope.Envelope;
            pAxMapControl.FlashShape(pPoint as IGeometry);
            //ccc(pPoint);
            //ddd(pPoint);
        }

 private void toolStripButton2_Click(object sender, EventArgs e)
 {
     IPoint pPoint = new PointClass();
     pPoint.PutCoords(Convert.ToDouble(txtlong.Text), Convert.ToDouble(txtlat.Text));
     IEnvelope pEnvelope = new EnvelopeClass();
     pEnvelope = pAxMapControl.Extent;
     //pEnvelope.Expand(10, -10, true);
     pEnvelope.Width = 20;
     pEnvelope.Height = 15;
     pEnvelope.CenterAt(pPoint);
     pAxMapControl.Extent = pEnvelope.Envelope;
     pAxMapControl.FlashShape(pPoint as IGeometry);
 }

        protected override void OnClick()
        {
            //
            //  TODO: Sample code showing how to access button host
            //

            var referenceFactory2 = (ISpatialReferenceFactory2)new SpatialReferenceEnvironment();
            ISpatialReference WGS84 = referenceFactory2.CreateSpatialReference((int)esriSRGeoCSType.esriSRGeoCS_WGS1984);
            IPointCollection pointCollection = new PolylineClass();

            // ------------- Ensure that both points have negative longitude values -------------------
            IPoint point = new PointClass();
            point.PutCoords(-170, 10); // Equivalent to 170 degrees WEST
            point.SpatialReference = WGS84;
            pointCollection.AddPoint(point);


            point = new PointClass();
            point.PutCoords(-200, 10); // Equivalent to 160 degrees EAST
            point.SpatialReference = WGS84;
            pointCollection.AddPoint(point);
            // -----------------------------------------------------------------------

            IPolyline polyline = (IPolyline)pointCollection;
            polyline.SpatialReference = WGS84;

            var geometryDefEdit = (IGeometryDefEdit)new GeometryDef();
            geometryDefEdit.GeometryType_2 = esriGeometryType.esriGeometryPolyline;
            geometryDefEdit.SpatialReference_2 = WGS84;

            var field = (IFieldEdit)new Field();
            field.Name_2 = "Shape";
            field.Type_2 = esriFieldType.esriFieldTypeGeometry;
            field.GeometryDef_2 = geometryDefEdit;

            var fields = (IFieldsEdit)new Fields();
            fields.AddField(field);

            IWorkspaceFactory workspaceFactory = new ShapefileWorkspaceFactory();
            var featureWorkspace = (IFeatureWorkspace)workspaceFactory.OpenFromFile("C:\\Temp\\", 0);
            IFeatureClass featureClass = featureWorkspace.CreateFeatureClass
                        ("test3.shp", fields, null, null, esriFeatureType.esriFTSimple, "Shape", "");

            var feature = featureClass.CreateFeature();
            feature.Shape = polyline;
            feature.Store();


            ArcMap.Application.CurrentTool = null;
        }