【小技巧】C#判断电脑是否联网

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

//添加特殊命名空间
using System.Runtime.InteropServices;

namespace GPS解析上位机_在线版_
{
    public partial class Form1 : Form
    {
        [DllImport("wininet")]
        //判断网络状况的方法,返回值true为连接，false为未连接  
        public extern static bool InternetGetConnectedState(out int conState, int reder); 

        public Form1()
        {
            InitializeComponent();

            int i = 0;
            if((InternetGetConnectedState(out i, 0)==true))
            {
                MessageBox.Show("设备联网正常！");
            }
            else
            {
                MessageBox.Show("设备不可联网！");
            }
        }

       private void Form1_Load(object sender, EventArgs e)
        {

        }
    }
}