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)        {        }    }}