64位系统下，利用c#获取ipv4的DNS

inPar = null;  outPar = null;  mc = new ManagementClass("Win32_NetworkAdapterConfiguration");  moc = mc.GetInstances();     foreach (ManagementObject mo in moc)  {      if (Convert.ToBoolean(mo["ipEnabled"]))      {          // 獲取Ip,子網掩碼,網關          ipAddress = (mo["IPAddress"] as string[])[0];          ipSubNet = (mo["IPSubnet"] as string[])[0];          ipGateway = (mo["DefaultIPGateway"] as string[])[0];             // 判斷DNS數量,並取值          int dnsCount = (mo["DNSServerSearchOrder"] as string[]).Length;          if (dnsCount > 0)          {              firstDns = (mo["DNSServerSearchOrder"] as string[])[0];          }          if (dnsCount > 1)          {              secondDns = (mo["DNSServerSearchOrder"] as string[])[1];          }          break;      }  }

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獲取本機ip本來是很容易的，IPAddress _ip = Dns.GetHostAddresses(Dns.GetHostName())[0];就行了

但是在vista win7等系統裡面這樣獲得的是ipv6地址，另外有多張網卡的時候問題就更複雜了

以前我都是根據自己的ip修改數組的下標，不過那樣畢竟不是好的辦法，用AddressFamily來判斷更好

以下是我自己查msdn寫出來的，思路就是先用GetHostAddresses獲得所有ip地址，然後找出ipv4地址，儲存在StringCollection裡面。當然如果只是想獲取第一個ip就不用寫這麼麻煩。

using System;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.Net.Sockets;
using System.Collections.Specialized;

namespace GetIpv4Test
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
ShowIP();
}
void ShowIP()
{
//ipv4地址也可能不止一個
foreach(string ip in GetLocalIpv4())
{
this.richTextBoxIPv4.AppendText(ip.ToString());
}
return;
}
string[] GetLocalIpv4()
{
//事先不知道ip的個數，數組長度未知，因此用StringCollection儲存
try
{
IPAddress[] localIPs;
localIPs = Dns.GetHostAddresses(Dns.GetHostName());
StringCollection IpCollection = new StringCollection();
foreach (IPAddress ip in localIPs)
{
//根據AddressFamily判斷是否為ipv4,如果是InterNetWork則為ipv6
if (ip.AddressFamily == AddressFamily.InterNetwork)
IpCollection.Add(ip.ToString());
}
string[] IpArray = new string[IpCollection.Count];
IpCollection.CopyTo(IpArray, 0);
return IpArray;
}
catch (Exception ex)
{
MessageBox.Show("Error: " + ex.Message);
}
return null;
}
}