C# 通过url获得ip地址

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Diagnostics;

public partial class Admin_BBSYear : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string ip = "www.sina.com";

this.Label1.Text = CmdPing(ip);
}
private static string CmdPing(string strIp)
{

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("exit");

string strRst = p.StandardOutput.ReadToEnd();

if (strRst.IndexOf("(0% loss)") != -1)
{
pingrst = "连接";
int start = strRst.IndexOf("Reply from");
int end = strRst.IndexOf(": bytes=");
pingrst = strRst.Remove(end);
pingrst = pingrst.Substring(start+10);
}
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 = "超时";

else if (strRst.IndexOf("Unknown host") != -1)

pingrst = "无法解析主机";

else

pingrst = strRst;

p.Close();

return pingrst;

}
}