asp.net C#判断电脑是否可以上网

public bool CheckForInternetConnection()
{
bool result = false;

try
{
Ping ping = new Ping();
PingReply replay = ping.Send("114.114.114.114", 2000);
if (replay.Status == IPStatus.Success)
{
result = true;
}
}
catch { }

return result;
}

public bool CheckForInternetConnection()
{
bool result = false;

try
{
using (WebClient client = new WebClient())
{
client.DownloadString("https://www.111cn.net/");
result = true;
}
}
catch { }

return result;
}

c#自带的Ping，using System.Net.NetworkInformation;
Ping ping = new Ping();
for (int i = iFrom; i {
mre1.WaitOne();
string ip = strIP + i.ToString();
label10.Text = "正在扫描主机：" + ip.ToString() ;
try
{
PingReply reply = ping.Send(ip, 100);
if (reply.Status == IPStatus.Success)
{
rtbInfo.AppendText("Host: " + ip.ToString() + "＼r");
rtbInfo.ScrollToCaret();
}
}
catch {
rtbInfo.AppendText("发生了一个异常！＼r");
}
}
rtbInfo.AppendText("扫描完毕!＼r");