1 using System;
  2 using System.Collections.Generic;
  3 using System.Text;
  4 //方法一
  5 using System.Runtime;
  6 using System.Runtime.InteropServices;
  7 //方法二 Net2.0新增类库
  8 using System.Net.NetworkInformation;
  9 
 10 namespace InternetCheck
 11 {
 12     public class Internet
 13     {
 14         [DllImport("wininet.dll")]
 15         private extern static bool InternetGetConnectedState(int Description, int ReservedValue);
 16 
 17         #region 方法一
 18         /// <summary>
 19         /// 用于检查网络是否可以连接互联网,true表示连接成功,false表示连接失败 
 20         /// </summary>
 21         /// <returns></returns>
 22         public static bool IsConnectInternet()
 23         {
 24             int Description = 0;
 25             return InternetGetConnectedState(Description, 0);
 26         }
 27         #endregion
 28 
 29         #region 方法二
 30         /// <summary>
 31         /// 用于检查IP地址或域名是否可以使用TCP/IP协议访问(使用Ping命令),true表示Ping成功,false表示Ping失败 
 32         /// </summary>
 33         /// <param name="strIpOrDName">输入参数,表示IP地址或域名</param>
 34         /// <returns></returns>
 35         public static bool PingIpOrDomainName(string strIpOrDName)
 36         {
 37             try
 38             {
 39                 Ping objPingSender = new Ping();
 40                 PingOptions objPinOptions = new PingOptions();
 41                 objPinOptions.DontFragment = true;
 42                 string data = "";
 43                 byte[] buffer = Encoding.UTF8.GetBytes(data);
 44                 int intTimeout = 120;
 45                 PingReply objPinReply = objPingSender.Send(strIpOrDName, intTimeout, buffer, objPinOptions);
 46                 string strInfo = objPinReply.Status.ToString();
 47                 if (strInfo == "Success")
 48                 {
 49                     return true;
 50                 }
 51                 else
 52                 {
 53                     return false;
 54                 }
 55             }
 56             catch (Exception)
 57             {
 58                 return false;
 59             }
 60         }
 61         #endregion
 62     }
 63 } 
 64 using System;
 65 using System.Collections.Generic;
 66 using System.Text;
 67 //方法一
 68 using System.Runtime;
 69 using System.Runtime.InteropServices;
 70 //方法二 Net2.0新增类库
 71 using System.Net.NetworkInformation;
 72 
 73 namespace InternetCheck
 74 {
 75     public class Internet
 76     {
 77         [DllImport("wininet.dll")]
 78         private extern static bool InternetGetConnectedState(int Description, int ReservedValue);
 79 
 80         #region 方法一
 81         /// <summary>
 82         /// 用于检查网络是否可以连接互联网,true表示连接成功,false表示连接失败 
 83         /// </summary>
 84         /// <returns></returns>
 85         public static bool IsConnectInternet()
 86         {
 87             int Description = 0;
 88             return InternetGetConnectedState(Description, 0);
 89         }
 90         #endregion
 91 
 92         #region 方法二
 93         /// <summary>
 94         /// 用于检查IP地址或域名是否可以使用TCP/IP协议访问(使用Ping命令),true表示Ping成功,false表示Ping失败 
 95         /// </summary>
 96         /// <param name="strIpOrDName">输入参数,表示IP地址或域名</param>
 97         /// <returns></returns>
 98         public static bool PingIpOrDomainName(string strIpOrDName)
 99         {
100             try
101             {
102                 Ping objPingSender = new Ping();
103                 PingOptions objPinOptions = new PingOptions();
104                 objPinOptions.DontFragment = true;
105                 string data = "";
106                 byte[] buffer = Encoding.UTF8.GetBytes(data);
107                 int intTimeout = 120;
108                 PingReply objPinReply = objPingSender.Send(strIpOrDName, intTimeout, buffer, objPinOptions);
109                 string strInfo = objPinReply.Status.ToString();
110                 if (strInfo == "Success")
111                 {
112                     return true;
113                 }
114                 else
115                 {
116                     return false;
117                 }
118             }
119             catch (Exception)
120             {
121                 return false;
122             }
123         }
124         #endregion
125     }
126 } 
127 
128 
129 // 本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/yhrch/archive/2007/11/05/1867546.aspx