C# 取得內網IP、外網IP、客戶端IP方法

 

前言

　　在 Windows Form Application 里對於取得 IP Address 有內網、外網兩種 IP Address ，如果只需要取得內網 IP Address ，可以透過使用 IPHostEntry 類別取得，而外網的話就必須要發送一個 Request 到一個可以取得 IP Address 的網站后再分析 Response 的內容，這個網站可以自己做或者使用現成的，如 http://www.whatismyip.com.tw/ 。

　　另外，在使用 Socket 通訊的情況下，也有可能有需要知道前來連結的客戶端的 IP Address 是什么，這時就可以使用 Socket.RemoteEndPoint 屬性來取得遠程 IP 地址和通訊端口編號，以下就列出范例代碼看看該如何使用。

范例程序代碼

/// <summary>
        /// 取得外網 IP Address
        /// </summary>
        /// <returns></returns>
        private string GetExtranetIPAddress()
        {
            HttpWebRequest request = HttpWebRequest.Create("http://www.whatismyip.com.tw") as HttpWebRequest;
            request.Method = "GET";
            request.ContentType = "application/x-www-form-urlencoded";
            request.UserAgent = "Mozilla/5.0";
            string ip = string.Empty;
            WebResponse response = request.GetResponse();
            using (StreamReader reader = new StreamReader(response.GetResponseStream()))
            {
                string result = reader.ReadToEnd();
                string pattern = @"\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}";
                ip = Regex.Match(result, pattern).ToString();
            }
            return ip; // result: 210.125.21.xxx
        }

/// <summary>
        /// 取得本機 IP Address
        /// </summary>
        /// <returns></returns>
        private List<string> GetHostIPAddress()
        {
            List<string> lstIPAddress = new List<string>();
            IPHostEntry IpEntry = Dns.GetHostEntry(Dns.GetHostName());
            foreach (IPAddress ipa in IpEntry.AddressList)
            {
                if (ipa.AddressFamily == AddressFamily.InterNetwork)
                    lstIPAddress.Add(ipa.ToString());
            }
            return lstIPAddress; // result: 192.168.1.17 ......
        }

 

private static string GetIP()
{
    string tempip = "";
    try
    {
        WebRequest wr = WebRequest.Create("http://www.ip138.com/ips138.asp");
        Stream s = wr.GetResponse().GetResponseStream();
        StreamReader sr = new StreamReader(s, Encoding.Default);
        string all = sr.ReadToEnd(); //讀取網站的數據

        int start = all.IndexOf("您的IP地址是：[") + 9;
        int end = all.IndexOf("]", start);
        tempip = all.Substring(start, end - start);
        sr.Close();
        s.Close();
    }
    catch
    {
    }
    return tempip;
}

 

 

 

/// <summary>
/// 執行服務器監聽
/// </summary>
public static void RunServer() 
{

    // 建立X509憑證
    ServerCertificate = new X509Certificate(Certificate, "ssl");
    // 監聽任何IP Address來的訊息
    listener = new TcpListener(System.Net.IPAddress.Any, 17170);
    // 開啟監聽
    listener.Start();

    while (IsRun)
    {
        TcpClient client = listener.AcceptTcpClient();

        ProcessClient(client);
    }
}

/// <summary>
/// 接收客戶端訊息處理並回復
/// </summary>
/// <param name="pClient"></param>
private static void ProcessClient(TcpClient pClient)
{
    SslStream sslStream = new SslStream(pClient.GetStream(), true);

    // 取得連接者 IP 與 Port
    IPEndPoint point = pClient.Client.RemoteEndPoint as IPEndPoint;
    string ip = point.Address.ToString(); // result: 127.0.0.1
    string port = point.Port.ToString(); // result: 55236

    // do something...
}

 

string tempIP =string.Empty;if (System.Net.Dns.GetHostEntry(System.Net.Dns.GetHostName()).AddressList.Length >1)     tempIP = System.Net.Dns.GetHostEntry(System.Net.Dns.GetHostName()).AddressList[1].ToString();

 

【ASP.NET開發】獲取客戶端IP地址 via C#