using System;
using System.Windows.Forms;

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

        private void Form1_Load(object sender, EventArgs e)
        {
            MessageBox.Show("欢迎使用两点距离计算器！");
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Point p1 = new Point(Convert.ToInt32(textBox1.Text), Convert.ToInt32(textBox2.Text));
            Point p2 = new Point(Convert.ToInt32(textBox3.Text), Convert.ToInt32(textBox4.Text));
            richTextBox1.Text = p1.Distance(p2).ToString();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            textBox1.Text = "";
            textBox2.Text = "";
            textBox3.Text = "";
            textBox4.Text = "";
            richTextBox1.Text = "";
        }
    }
    class Point
    {
        private int x;
        private int y;
        public Point(int x, int y)
        {
            this.x = x;
            this.y = y;
        }
        public int X
        {
            get
            {
                return x;
            }
        }
        public int Y
        {
            get
            {
                return y;
            }
        }
        public double Distance(Point p)
        {
            return System.Math.Sqrt((this.X - p.X) * (this.X - p.X) + (this.Y - p.Y) * (this.Y - p.Y));
        }
    }
}