GPS轨迹压缩之Douglas-Peucker算法之C# winform实现，代码包括导入.txt经度纬度数据，输出压缩后的文本

好的，这里为您提供一份C# Winform实现的GPS轨迹压缩代码，包括导入.txt经度纬度数据和输出压缩后的文本。代码如下：

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Windows.Forms;

namespace DouglasPeuckerAlgorithm
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void btnImport_Click(object sender, EventArgs e)
        {
            OpenFileDialog openFileDialog = new OpenFileDialog();
            openFileDialog.Filter = "Text Files (*.txt)|*.txt";
            if (openFileDialog.ShowDialog() == DialogResult.OK)
            {
                string filePath = openFileDialog.FileName;
                List<Point> points = ReadPointsFromFile(filePath);
                if (points != null && points.Count > 0)
                {
                    double epsilon = 0.001; // 压缩精度
                    List<int> results = DouglasPeucker(points, 0, points.Count - 1, epsilon);
                    string outputText = string.Join("\r\n", results.Select(i => $"{points[i].X},{points[i].Y}"));
                    txtOutput.Text = outputText;
                }
                else
                {
                    MessageBox.Show("无法读取数据", "错误", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
            }
        }

        private List<Point> ReadPointsFromFile(string filePath)
        {
            try
            {
                List<Point> points = new List<Point>();
                using (StreamReader reader = new StreamReader(filePath))
                {
                    string line;
                    while ((line = reader.ReadLine()) != null)
                    {
                        string[] values = line.Split(',');
                        if (values.Length == 2 && double.TryParse(values[0], out double x) && double.TryParse(values[1], out double y))
                        {
                            points.Add(new Point(x, y));
                        }
                    }
                }
                return points;
            }
            catch (Exception)
            {
                return null;
            }
        }

        private List<int> DouglasPeucker(List<Point> points, int start, int end, double epsilon)
        {
            double dmax = 0;
            int index = 0;
            for (int i = start + 1; i < end; i++)
            {
                double d = PointToLineDistance(points[i], points[start], points[end]);
                if (d > dmax)
                {
                    dmax = d;
                    index = i;
                }
            }
            List<int> results = new List<int>();
            if (dmax > epsilon)
            {
                List<int> leftResults = DouglasPeucker(points, start, index, epsilon);
                List<int> rightResults = DouglasPeucker(points, index, end, epsilon);
                results = leftResults.Concat(rightResults.Skip(1)).ToList();
            }
            else
            {
                results.Add(start);
            }
            return results;
        }

        private double PointToLineDistance(Point p, Point p1, Point p2)
        {
            double dx = p2.X - p1.X;
            double dy = p2.Y - p1.Y;
            double d = dx * dx + dy * dy;
            double u = ((p.X - p1.X) * dx + (p.Y - p1.Y) * dy) / d;
            Point pt;
            if (u < 0)
            {
                pt = p1;
            }
            else if (u > 1)
            {
                pt = p2;
            }
            else
            {
                pt = new Point(p1.X + u * dx, p1.Y + u * dy);
            }
            return Math.Sqrt((p.X - pt.X) * (p.X - pt.X) + (p.Y - pt.Y) * (p.Y - pt.Y));
        }

        private class Point
        {
            public double X { get; set; }
            public double Y { get; set; }

            public Point(double x, double y)
            {
                X = x;
                Y = y;
            }
        }
    }
}

需要注意的是，这份代码是基于C#的Winform框架实现的，需要在Visual Studio等开发环境中使用。在界面中，有一个导入按钮(btnImport)和一个输出文本框(txtOutput)，通过点击导入按钮可以从.txt文件中读取经度纬度数据，然后进行轨迹压缩并输出到文本框中。在DouglasPeucker函数中，压缩精度epsilon可以根据实际需求进行调整。