asp.net 判断能否连网 可以 返回1 不可以返回0

Question

谢谢

Answer 1

try
{
System.Net.WebClient wc =new System.Net.WebClient();
string bb=wc.DownloadString("http://www.baidu.com");
}
catch(Exception ex)
{
  //没有联网
  return "我就不返回0";
}

Answer 2

wininet
[DllImport("wininet")]
        private extern static bool InternetGetConnectedState(out int connectionDescription, int reservedValue);
        ///<summary>
        /// 检测本机的网络连接
        ///</summary>
 
       private void button1_Click(object sender, EventArgs e)
        {
            //判断是否联网
                int i = 0;
                if (InternetGetConnectedState(out i, 0))
                {
                    //联网
                    MessageBox.Show("Thylx提醒您：你的计算机已连接到网络上！");
                 }
                 else
                  {
                     //断网
                     MessageBox.Show("Thylx提醒您：本地连接已断开！");
                  }
        }

Answer 3

process通过cmd ping
[DllImport("wininet.dll")]
  private extern static bool InternetGetConnectedState(out int connectionDescription, int reservedValue);
  public bool IsInternetConnected()
  {
  int i = 0;
  return InternetGetConnectedState(out i, 0);
  }

Answer 4

        private string CheckNetWork(string _strUrl)
        {
            //实例一个Process类，启动一个独立进程
            Process p = new Process();            p.StartInfo.FileName = "cmd.exe";
            p.StartInfo.UseShellExecute = false;
            p.StartInfo.RedirectStandardInput = true;
            p.StartInfo.RedirectStandardOutput = true;
            p.StartInfo.RedirectStandardError = true;
            p.StartInfo.CreateNoWindow = true;
            string PingRst;
            p.Start();
            p.StandardInput.WriteLine("ping -n 1 " + _strIP);
            //p.StandardInput.WriteLine("telnet -n 1 " + _strIP + " 84564646");
            p.StandardInput.WriteLine("exit");
            string strRst = p.StandardOutput.ReadToEnd();
            //strRst = p.StandardError.ReadToEnd();
            //p.WaitForExit();
            if (strRst.IndexOf("(0% loss)") != -1)
                PingRst = "连接";
            else if (strRst.IndexOf("Destination host unreachable.") != -1)
                PingRst = "无法到达目的主机";
            else if (strRst.IndexOf("Request timed out.") != -1)
                PingRst = "网络连接超时";
            else if (strRst.IndexOf("Unknown host") != -1)
                PingRst = "无法解析主机";
            else
                PingRst = "网络无效";
            p.Close();
            return PingRst;        }

Answer 5

这个方法其实也行ping一下百度