arcgis engine在地图上任意画两个多边形，分别实现两个多边形的逻辑运算(交集，并集，差集)代码

以下是示例代码，实现了在 ArcGIS Engine 上任意画两个多边形，并对它们进行交集、并集、差集运算：

using ESRI.ArcGIS.Carto;
using ESRI.ArcGIS.Controls;
using ESRI.ArcGIS.Geometry;
using ESRI.ArcGIS.SystemUI;
using System;
using System.Drawing;
using System.Windows.Forms;

namespace PolygonOperations
{
    public partial class MainForm : Form
    {
        private IToolbarMenu m_menu;
        private IGraphicsContainer m_graphicsContainer;
        private IActiveView m_activeView;
        private IPolygon m_polygon1;
        private IPolygon m_polygon2;

        public MainForm()
        {
            InitializeComponent();
        }

        private void MainForm_Load(object sender, EventArgs e)
        {
            // 初始化 ArcGIS Engine 控件
            axMapControl1.LoadMxFile(@"C:\data\map.mxd");
            m_graphicsContainer = axMapControl1.ActiveView.GraphicsContainer;
            m_activeView = axMapControl1.ActiveView;

            // 创建一个右键菜单，包含三个子菜单：交集、并集、差集
            m_menu = new ToolbarMenuClass();
            m_menu.AddItem(new IntersectMenuItem(this));
            m_menu.AddItem(new UnionMenuItem(this));
            m_menu.AddItem(new DifferenceMenuItem(this));
        }

        private void axMapControl1_OnMouseDown(object sender, IMapControlEvents2_OnMouseDownEvent e)
        {
            // 鼠标左键单击画多边形
            if (e.button == 1)
            {
                if (m_polygon1 == null)
                {
                    m_polygon1 = DrawPolygon();
                }
                else if (m_polygon2 == null)
                {
                    m_polygon2 = DrawPolygon();
                }
            }
            // 鼠标右键单击打开右键菜单
            else if (e.button == 2)
            {
                m_menu.PopupMenu(e.x, e.y, axMapControl1.hWnd);
            }
        }

        private IPolygon DrawPolygon()
        {
            // 在地图上画多边形
            IGeometry geometry = axMapControl1.TrackPolygon();
            if (geometry == null)
                return null;

            // 设置多边形的符号
            ISimpleFillSymbol fillSymbol = new SimpleFillSymbolClass();
            fillSymbol.Color = GetRandomColor();
            ISymbol symbol = fillSymbol as ISymbol;
            symbol.ROP2 = esriRasterOpCode.esriROPNotXOrPen;

            // 把多边形添加到图形容器中
            IElement element = new PolygonElementClass();
            element.Geometry = geometry;
            element.Symbol = symbol;
            m_graphicsContainer.AddElement(element, 0);

            // 刷新地图显示
            m_activeView.PartialRefresh(esriViewDrawPhase.esriViewGraphics, null, null);
            return geometry as IPolygon;
        }

        private Color GetRandomColor()
        {
            // 获取随机颜色
            Random rand = new Random();
            return Color.FromArgb(rand.Next(255), rand.Next(255), rand.Next(255));
        }

        public void Intersect()
        {
            // 计算两个多边形的交集
            if (m_polygon1 == null || m_polygon2 == null)
                return;
            ITopologicalOperator topoOp = m_polygon1 as ITopologicalOperator;
            IGeometry result = topoOp.Intersect(m_polygon2, esriGeometryDimension.esriGeometry2Dimension);
            ShowResult(result);
        }

        public void Union()
        {
            // 计算两个多边形的并集
            if (m_polygon1 == null || m_polygon2 == null)
                return;
            ITopologicalOperator topoOp = m_polygon1 as ITopologicalOperator;
            IGeometry result = topoOp.Union(m_polygon2);
            ShowResult(result);
        }

        public void Difference()
        {
            // 计算两个多边形的差集
            if (m_polygon1 == null || m_polygon2 == null)
                return;
            ITopologicalOperator topoOp = m_polygon1 as ITopologicalOperator;
            IGeometry result = topoOp.Difference(m_polygon2);
            ShowResult(result);
        }

        private void ShowResult(IGeometry geometry)
        {
            // 显示运算结果
            if (geometry == null)
                return;
            IElement element = new PolygonElementClass();
            element.Geometry = geometry;
            ISimpleFillSymbol fillSymbol = new SimpleFillSymbolClass();
            fillSymbol.Color = Color.Yellow;
            ISymbol symbol = fillSymbol as ISymbol;
            symbol.ROP2 = esriRasterOpCode.esriROPNotXOrPen;
            element.Symbol = symbol;
            m_graphicsContainer.AddElement(element, 0);
            m_activeView.PartialRefresh(esriViewDrawPhase.esriViewGraphics, null, null);
        }
    }

    public class IntersectMenuItem : IToolbarMenuEvent
    {
        private MainForm m_form;

        public IntersectMenuItem(MainForm form)
        {
            m_form = form;
        }

        public void OnItemClick()
        {
            m_form.Intersect();
        }
    }

    public class UnionMenuItem : IToolbarMenuEvent
    {
        private MainForm m_form;

        public UnionMenuItem(MainForm form)
        {
            m_form = form;
        }

        public void OnItemClick()
        {
            m_form.Union();
        }
    }

    public class DifferenceMenuItem : IToolbarMenuEvent
    {
        private MainForm m_form;

        public DifferenceMenuItem(MainForm form)
        {
            m_form = form;
        }

        public void OnItemClick()
        {
            m_form.Difference();
        }
    }
}

代码中定义了一个 MainForm 类，包含一个 ArcGIS Engine 控件和一个右键菜单，用于实现多边形运算。在 MainForm_Load 方法中初始化 ArcGIS Engine 控件和右键菜单，在 axMapControl1_OnMouseDown 方法中实现画多边形的功能，在 Intersect、Union、Difference 方法中分别计算多边形的交集、并集、差集，在 ShowResult 方法中显示运算结果。

在 IntersectMenuItem、UnionMenuItem、DifferenceMenuItem 类中分别实现右键菜单中的子菜单，用于调用 MainForm 中的 Intersect、Union、Difference 方法。