ArcEngine编辑模块——将线段按距离、按比例分割成N条线段

本文主要是介绍ArcEngine编辑模块——将线段按距离、按比例分割成N条线段，对大家解决编程问题具有一定的参考价值，需要的程序猿们随着小编来一起学习吧！

1、前言

前面一篇博客介绍了如何按距离或按比例将1条线段分成2条线段的方法，核心就是利用IFeatureEdit接口的Split方法进行分割。但就像之前说的，该方法只适用于将1条线段分成2条线段，如果我们希望将1条线段分成n条线段（n >= 2），那又该怎么做呢？下面开始介绍。

2、获取分割点

假设有一条长度为100米的线段，现在按照30米的距离间隔对其进行分割，那么就会得到如下图所示的结果，线段被A、B、C三个分割点分成了4份，

现在第一个问题来了：如何获取这些分割点？其实这个问题很简单，在IPolyline接口中有一个QueryPoint方法，该方法可以在指定的距离处获取线上的一点，我们可以来测试一下：

获取分割点代码

using ESRI.ArcGIS.ADF.BaseClasses;
using ESRI.ArcGIS.ADF.CATIDs;
using ESRI.ArcGIS.Carto;
using ESRI.ArcGIS.Controls;
using ESRI.ArcGIS.Display;
using ESRI.ArcGIS.esriSystem;
using ESRI.ArcGIS.Geodatabase;
using ESRI.ArcGIS.Geometry;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace WindowsFormsApplication1.Command
{
    /// <summary>
    /// Summary description for SplitByDistanceCommand.
    /// </summary>
    [Guid("b8a71064-25d0-4816-9b9a-0f3738ddf981")]
    [ClassInterface(ClassInterfaceType.None)]
    [ProgId("WindowsFormsApplication1.Command.SplitByDistanceCommand")]
    public sealed class SplitByDistanceCommand : BaseCommand
    {
        #region COM Registration Function(s)
        [ComRegisterFunction()]
        [ComVisible(false)]
        static void RegisterFunction(Type registerType)
        {
            // Required for ArcGIS Component Category Registrar support
            ArcGISCategoryRegistration(registerType);

            //
            // TODO: Add any COM registration code here
            //
        }

        [ComUnregisterFunction()]
        [ComVisible(false)]
        static void UnregisterFunction(Type registerType)
        {
            // Required for ArcGIS Component Category Registrar support
            ArcGISCategoryUnregistration(registerType);

            //
            // TODO: Add any COM unregistration code here
            //
        }

        #region ArcGIS Component Category Registrar generated code
        /// <summary>
        /// Required method for ArcGIS Component Category registration -
        /// Do not modify the contents of this method with the code editor.
        /// </summary>
        private static void ArcGISCategoryRegistration(Type registerType)
        {
            string regKey = string.Format("HKEY_CLASSES_ROOT\\CLSID\\{{{0}}}", registerType.GUID);
            ControlsCommands.Register(regKey);

        }
        /// <summary>
        /// Required method for ArcGIS Component Category unregistration -
        /// Do not modify the contents of this method with the code editor.
        /// </summary>
        private static void ArcGISCategoryUnregistration(Type registerType)
        {
            string regKey = string.Format("HKEY_CLASSES_ROOT\\CLSID\\{{{0}}}", registerType.GUID);
            ControlsCommands.Unregister(regKey);

        }

        #endregion
        #endregion

        private IHookHelper m_hookHelper;

        public SplitByDistanceCommand()
        {
            //
            // TODO: Define values for the public properties
            //
            base.m_category = ""; //localizable text
            base.m_caption = "";  //localizable text
            base.m_message = "";  //localizable text 
            base.m_toolTip = "";  //localizable text 
            base.m_name = "";   //unique id, non-localizable (e.g. "MyCategory_MyCommand")

            try
            {
                //
                // TODO: change bitmap name if necessary
                //
                string bitmapResourceName = GetType().Name + ".bmp";
                base.m_bitmap = new Bitmap(GetType(), bitmapResourceName);
            }
            catch (Exception ex)
            {
                System.Diagnostics.Trace.WriteLine(ex.Message, "Invalid Bitmap");
            }
        }

        #region Overridden Class Methods

        /// <summary>
        /// Occurs when this command is created
        /// </summary>
        /// <param name="hook">Instance of the application</param>
        public override void OnCreate(object hook)
        {
            if (hook == null)
                return;

            if (m_hookHelper == null)
                m_hookHelper = new HookHelperClass();

            m_hookHelper.Hook = hook;

            // TODO:  Add other initialization code
        }

        /// <summary>
        /// Occurs when this command is clicked
        /// </summary>
        public override void OnClick()
        {
            if (m_hookHelper.FocusMap.SelectionCount != 1)
            {
                MessageBox.Show("请选择1条线要素进行分割", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }

            // 获取被选择的要素
            IEnumFeature pEnumFeature = m_hookHelper.FocusMap.FeatureSelection as IEnumFeature;
            pEnumFeature.Reset();
            IFeature pFeature = pEnumFeature.Next();
            if (pFeature.Shape is IPoint || pFeature.Shape is IPolygon)
            {
                MessageBox.Show("请选择1条线要素进行分割", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }

            // 获取分割点
            IPolyline pPolyline = pFeature.ShapeCopy as IPolyline;
            List<IPoint> points = new List<IPoint>();
            double distance = 50;
            double interval = 50;
            while (distance < pPolyline.Length)
            {
                IPoint pPoint = new ESRI.ArcGIS.Geometry.Point();
                pPolyline.QueryPoint(esriSegmentExtension.esriNoExtension, distance, false, pPoint);
                points.Add(pPoint);
                distance += interval;
            }

            // 创建颜色
            IRgbColor pRgbColor = new RgbColor();
            pRgbColor.Red = 255;
            pRgbColor.Green = 0;
            pRgbColor.Blue = 0;

            // 创建点符号
            ISimpleMarkerSymbol pSimpleMarkerSymbol = new SimpleMarkerSymbol();
            pSimpleMarkerSymbol.Color = pRgbColor;
            pSimpleMarkerSymbol.Size = 15;
            pSimpleMarkerSymbol.Style = esriSimpleMarkerStyle.esriSMSCircle;

            // 绘制分割点
            foreach (IPoint pPoint in points)
            {
                IMarkerElement pMarkerElement = new MarkerElement() as IMarkerElement;
                pMarkerElement.Symbol = pSimpleMarkerSymbol;
                IElement pElement = pMarkerElement as IElement;
                pElement.Geometry = pPoint;
                m_hookHelper.ActiveView.GraphicsContainer.AddElement(pElement, 0);
            }

            // 刷新地图
            m_hookHelper.ActiveView.Refresh();
        }
        #endregion
    }
}

运行结果如下图所示，可以发现：这条线段长度为164米，按照50米的距离间隔对其进行分割，结果在50米、100米、150米处产生了3个分割点。

3、分割操作的结束条件

现在需要思考一下：分割操作的结束条件是什么？还是上面的情景，我们来模拟一下：

• 获取长度为164米的线段，在50米处执行分割操作，得到50米和114米两条线段
• 获取长度为114米的线段，在50米处执行分割操作，得到50米和64米两条线段
• 获取长度为64米的线段，在50米处执行分割操作，得到50米和14米两条线段
• 由于50米和14米这两条线段的长度均小于等于50米，因此不再执行分割操作。

通过上面的分析可以得出结论：

• 每次分割的对象都是距离较长的那条线段
• 当执行分割操作后的两条线段长度均小于等于指定的距离间隔时，分割结束

4、距离分割

4.1、主界面代码

using ESRI.ArcGIS.Controls;
using ESRI.ArcGIS.SystemUI;
using System;
using System.Windows.Forms;
using WindowsFormsApplication1.Command;

namespace WindowsFormsApplication1
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
            axMapControl1.LoadMxFile(@"C:\Users\DSF\Desktop\data\无标题.mxd");
            axMapControl1.Extent = axMapControl1.FullExtent;
            btnStartEditing.Enabled = true;
            btnStopEditing.Enabled = false;
            btnSelect.Enabled = false;
            btnSplitByDistance.Enabled = false;
            btnSplitByRatio.Enabled = false;
        }

        // 开始编辑
        private void btnStartEditing_Click(object sender, EventArgs e)
        {
            ICommand command = new ControlsEditingStartCommand();
            command.OnCreate(axMapControl1.Object);
            command.OnClick();

            btnStartEditing.Enabled = false;
            btnStopEditing.Enabled = true;
            btnSelect.Enabled = true;
            btnSplitByDistance.Enabled = true;
            btnSplitByRatio.Enabled = true;
        }

        // 结束编辑
        private void btnStopEditing_Click(object sender, EventArgs e)
        {
            ICommand saveCommand = new ControlsEditingSaveCommand();
            saveCommand.OnCreate(axMapControl1.Object);
            saveCommand.OnClick();

            ICommand clearSelectionCommand = new ControlsClearSelectionCommand();
            clearSelectionCommand.OnCreate(axMapControl1.Object);
            clearSelectionCommand.OnClick();

            btnStartEditing.Enabled = true;
            btnStopEditing.Enabled = false;
            btnSelect.Enabled = false;
            btnSplitByDistance.Enabled = false;
            btnSplitByRatio.Enabled = false;
        }

        // 选择要素
        private void btnSelect_Click(object sender, EventArgs e)
        {
            ICommand command = new ControlsSelectFeaturesTool();
            command.OnCreate(axMapControl1.Object);
            axMapControl1.CurrentTool = command as ITool;
        }

        // 距离分割
        private void btnSplitByDistance_Click(object sender, EventArgs e)
        {
            ICommand command = new SplitByDistanceCommand();
            command.OnCreate(axMapControl1.Object);
            command.OnClick();
        }

        // 比例分割
        private void btnSplitByRatio_Click(object sender, EventArgs e)
        {
            ICommand command = new SplitByRatioCommand();
            command.OnCreate(axMapControl1.Object);
            command.OnClick();
        }
    }
}

4.2、距离分割代码

using ESRI.ArcGIS.ADF.BaseClasses;
using ESRI.ArcGIS.ADF.CATIDs;
using ESRI.ArcGIS.Controls;
using ESRI.ArcGIS.esriSystem;
using ESRI.ArcGIS.Geodatabase;
using ESRI.ArcGIS.Geometry;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace WindowsFormsApplication1.Command
{
    /// <summary>
    /// Summary description for SplitByDistanceCommand.
    /// </summary>
    [Guid("b8a71064-25d0-4816-9b9a-0f3738ddf981")]
    [ClassInterface(ClassInterfaceType.None)]
    [ProgId("WindowsFormsApplication1.Command.SplitByDistanceCommand")]
    public sealed class SplitByDistanceCommand : BaseCommand
    {
        #region COM Registration Function(s)
        [ComRegisterFunction()]
        [ComVisible(false)]
        static void RegisterFunction(Type registerType)
        {
            // Required for ArcGIS Component Category Registrar support
            ArcGISCategoryRegistration(registerType);

            //
            // TODO: Add any COM registration code here
            //
        }

        [ComUnregisterFunction()]
        [ComVisible(false)]
        static void UnregisterFunction(Type registerType)
        {
            // Required for ArcGIS Component Category Registrar support
            ArcGISCategoryUnregistration(registerType);

            //
            // TODO: Add any COM unregistration code here
            //
        }

        #region ArcGIS Component Category Registrar generated code
        /// <summary>
        /// Required method for ArcGIS Component Category registration -
        /// Do not modify the contents of this method with the code editor.
        /// </summary>
        private static void ArcGISCategoryRegistration(Type registerType)
        {
            string regKey = string.Format("HKEY_CLASSES_ROOT\\CLSID\\{{{0}}}", registerType.GUID);
            ControlsCommands.Register(regKey);

        }
        /// <summary>
        /// Required method for ArcGIS Component Category unregistration -
        /// Do not modify the contents of this method with the code editor.
        /// </summary>
        private static void ArcGISCategoryUnregistration(Type registerType)
        {
            string regKey = string.Format("HKEY_CLASSES_ROOT\\CLSID\\{{{0}}}", registerType.GUID);
            ControlsCommands.Unregister(regKey);

        }

        #endregion
        #endregion

        private IHookHelper m_hookHelper;

        public SplitByDistanceCommand()
        {
            //
            // TODO: Define values for the public properties
            //
            base.m_category = ""; //localizable text
            base.m_caption = "";  //localizable text
            base.m_message = "";  //localizable text 
            base.m_toolTip = "";  //localizable text 
            base.m_name = "";   //unique id, non-localizable (e.g. "MyCategory_MyCommand")

            try
            {
                //
                // TODO: change bitmap name if necessary
                //
                string bitmapResourceName = GetType().Name + ".bmp";
                base.m_bitmap = new Bitmap(GetType(), bitmapResourceName);
            }
            catch (Exception ex)
            {
                System.Diagnostics.Trace.WriteLine(ex.Message, "Invalid Bitmap");
            }
        }

        #region Overridden Class Methods

        /// <summary>
        /// Occurs when this command is created
        /// </summary>
        /// <param name="hook">Instance of the application</param>
        public override void OnCreate(object hook)
        {
            if (hook == null)
                return;

            if (m_hookHelper == null)
                m_hookHelper = new HookHelperClass();

            m_hookHelper.Hook = hook;

            // TODO:  Add other initialization code
        }

        /// <summary>
        /// Occurs when this command is clicked
        /// </summary>
        public override void OnClick()
        {
            if (m_hookHelper.FocusMap.SelectionCount != 1)
            {
                MessageBox.Show("请选择1条线要素进行分割", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }

            // 获取被选择的要素
            IEnumFeature pEnumFeature = m_hookHelper.FocusMap.FeatureSelection as IEnumFeature;
            pEnumFeature.Reset();
            IFeature pFeature = pEnumFeature.Next();
            if (pFeature.Shape is IPoint || pFeature.Shape is IPolygon)
            {
                MessageBox.Show("请选择1条线要素进行分割", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }

            // 获取分割点
            IPolyline pPolyline = pFeature.ShapeCopy as IPolyline;
            List<IPoint> points = new List<IPoint>();
            double distance = 50;
            double interval = 50;
            while (distance < pPolyline.Length)
            {
                IPoint pPoint = new ESRI.ArcGIS.Geometry.Point();
                pPolyline.QueryPoint(esriSegmentExtension.esriNoExtension, distance, false, pPoint);
                points.Add(pPoint);
                distance += interval;
            }

            // 分割线要素
            foreach (IPoint pPoint in points)
            {
                IFeatureEdit pFeatureEdit = pFeature as IFeatureEdit;
                ISet pSet = pFeatureEdit.Split(pPoint);
                pSet.Reset();
                pFeature = GetFeatureByDistance(pSet);
            }

            // 刷新地图
            m_hookHelper.ActiveView.Refresh();
        }

        // 获取Set中距离较长的线要素
        private IFeature GetFeatureByDistance(ISet pSet)
        {
            IFeature pFirstFeature = pSet.Next() as IFeature;
            IFeature pSecondFeature = pSet.Next() as IFeature;
            IPolyline pFirstPolyline = pFirstFeature.ShapeCopy as IPolyline;
            IPolyline pSecondPolyline = pSecondFeature.ShapeCopy as IPolyline;
            return pFirstPolyline.Length <= pSecondPolyline.Length ? pSecondFeature : pFirstFeature;
        }
        #endregion
    }
}

运行结果如下图所示：

5、比例分割

比例分割如下图所示：

其实和按距离分割的逻辑差不多，唯一的区别就是在获取分割点时改为按比例获取，其代码如下：

using ESRI.ArcGIS.ADF.BaseClasses;
using ESRI.ArcGIS.ADF.CATIDs;
using ESRI.ArcGIS.Controls;
using ESRI.ArcGIS.esriSystem;
using ESRI.ArcGIS.Geodatabase;
using ESRI.ArcGIS.Geometry;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace WindowsFormsApplication1.Command
{
    /// <summary>
    /// Summary description for SplitByRatioCommand.
    /// </summary>
    [Guid("d4624838-4abc-458e-b6cf-fb5d78562e96")]
    [ClassInterface(ClassInterfaceType.None)]
    [ProgId("WindowsFormsApplication1.Command.SplitByRatioCommand")]
    public sealed class SplitByRatioCommand : BaseCommand
    {
        #region COM Registration Function(s)
        [ComRegisterFunction()]
        [ComVisible(false)]
        static void RegisterFunction(Type registerType)
        {
            // Required for ArcGIS Component Category Registrar support
            ArcGISCategoryRegistration(registerType);

            //
            // TODO: Add any COM registration code here
            //
        }

        [ComUnregisterFunction()]
        [ComVisible(false)]
        static void UnregisterFunction(Type registerType)
        {
            // Required for ArcGIS Component Category Registrar support
            ArcGISCategoryUnregistration(registerType);

            //
            // TODO: Add any COM unregistration code here
            //
        }

        #region ArcGIS Component Category Registrar generated code
        /// <summary>
        /// Required method for ArcGIS Component Category registration -
        /// Do not modify the contents of this method with the code editor.
        /// </summary>
        private static void ArcGISCategoryRegistration(Type registerType)
        {
            string regKey = string.Format("HKEY_CLASSES_ROOT\\CLSID\\{{{0}}}", registerType.GUID);
            ControlsCommands.Register(regKey);

        }
        /// <summary>
        /// Required method for ArcGIS Component Category unregistration -
        /// Do not modify the contents of this method with the code editor.
        /// </summary>
        private static void ArcGISCategoryUnregistration(Type registerType)
        {
            string regKey = string.Format("HKEY_CLASSES_ROOT\\CLSID\\{{{0}}}", registerType.GUID);
            ControlsCommands.Unregister(regKey);

        }

        #endregion
        #endregion

        private IHookHelper m_hookHelper;

        public SplitByRatioCommand()
        {
            //
            // TODO: Define values for the public properties
            //
            base.m_category = ""; //localizable text
            base.m_caption = "";  //localizable text
            base.m_message = "";  //localizable text 
            base.m_toolTip = "";  //localizable text 
            base.m_name = "";   //unique id, non-localizable (e.g. "MyCategory_MyCommand")

            try
            {
                //
                // TODO: change bitmap name if necessary
                //
                string bitmapResourceName = GetType().Name + ".bmp";
                base.m_bitmap = new Bitmap(GetType(), bitmapResourceName);
            }
            catch (Exception ex)
            {
                System.Diagnostics.Trace.WriteLine(ex.Message, "Invalid Bitmap");
            }
        }

        #region Overridden Class Methods

        /// <summary>
        /// Occurs when this command is created
        /// </summary>
        /// <param name="hook">Instance of the application</param>
        public override void OnCreate(object hook)
        {
            if (hook == null)
                return;

            if (m_hookHelper == null)
                m_hookHelper = new HookHelperClass();

            m_hookHelper.Hook = hook;
        }

        /// <summary>
        /// Occurs when this command is clicked
        /// </summary>
        public override void OnClick()
        {
            if (m_hookHelper.FocusMap.SelectionCount != 1)
            {
                MessageBox.Show("请选择1条线要素进行分割", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }

            // 获取被选择的要素
            IEnumFeature pEnumFeature = m_hookHelper.FocusMap.FeatureSelection as IEnumFeature;
            pEnumFeature.Reset();
            IFeature pFeature = pEnumFeature.Next();
            if (pFeature.Shape is IPoint || pFeature.Shape is IPolygon)
            {
                MessageBox.Show("请选择1条线要素进行分割", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }

            // 获取分割点
            IPolyline pPolyline = pFeature.ShapeCopy as IPolyline;
            List<IPoint> points = new List<IPoint>();
            double ratio = 0.2;
            double interval = 0.2;
            while (ratio < 1)
            {
                IPoint pPoint = new ESRI.ArcGIS.Geometry.Point();
                pPolyline.QueryPoint(esriSegmentExtension.esriNoExtension, ratio, true, pPoint);
                points.Add(pPoint);
                ratio += interval;
            }

            // 分割线要素
            foreach (IPoint pPoint in points)
            {
                IFeatureEdit pFeatureEdit = pFeature as IFeatureEdit;
                ISet pSet = pFeatureEdit.Split(pPoint);
                pSet.Reset();
                pFeature = GetFeatureByDistance(pSet);
            }

            // 刷新地图
            m_hookHelper.ActiveView.Refresh();
        }

        // 获取Set中距离较长的线要素
        private IFeature GetFeatureByDistance(ISet pSet)
        {
            IFeature pFirstFeature = pSet.Next() as IFeature;
            IFeature pSecondFeature = pSet.Next() as IFeature;
            IPolyline pFirstPolyline = pFirstFeature.ShapeCopy as IPolyline;
            IPolyline pSecondPolyline = pSecondFeature.ShapeCopy as IPolyline;
            return pFirstPolyline.Length <= pSecondPolyline.Length ? pSecondFeature : pFirstFeature;
        }
        #endregion
    }
}

运行结果如下图所示：

如果你想实现：对一条线段进行等比例分割，那么只需要修改一下分割比例即可。比如对1条线段5等分只需要将分割比例设置为0.2即可：

double ratio = 0.2;
double interval = 0.2;

运行结果如下图所示：

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