C# 如果判断网址是否正确,C#判断 URL是否正确,正则表达式

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Text.RegularExpressions;

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

        private void button1_Click(object sender, EventArgs e)
        {
            string websitereg = @"http://([\w-]+\.)+[\w-]+(/[\w- ./?%&=]*)?";
            Match w1 = Regex.Match(textBox1.Text, websitereg);
            if (w1.Success)
            {
                MessageBox.Show("yes");
            }
            else
            {
                MessageBox.Show("no");
            }
        }

    }
}