函数原型：函数InternetGetConnectedState返回本地系统的网络连接状态。
语法：
BOOL InternetGetConnectedState(
__out LPDWORD lpdwFlags,
__in DWORD dwReserved
);
参数：
lpdwFlags[out]
指向一个变量，该变量接收连接描述内容。该参数在函数返回FLASE时仍可以返回一个有效的标记。该参数可以为下列值的一个或多个
|
值
|
含义
|
|---|---|
|
INTERNET_CONNECTION_CONFIGURED
0x40(64)
|
Local system has a valid connection to the Internet, but it might or might not be currently connected.
|
|
INTERNET_CONNECTION_LAN
0x02(2)
|
Local system uses a local area network to connect to the Internet.
|
|
INTERNET_CONNECTION_MODEM0
x01(1)
|
Local system uses a modem to connect to the Internet.
|
|
INTERNET_CONNECTION_MODEM_BUSY0
x08(8)
|
No longer used.
|
|
INTERNET_CONNECTION_OFFLINE
0x20(16)
|
Local system is in offline mode.
|
|
INTERNET_CONNECTION_PROXY
0x04(4)
|
Local system uses a proxy server to connect to the Internet.
|
|
INTERNET_RAS_INSTALLED
0x10(8)
|
Local system has RAS installed.
|
dwReserved[in]
保留值。必须为0。
当存在一个modem或一个LAN连接时，返回TRUE，当不存在internet连接或所有的连接当前未被激活时，返回false。
当该函数返回false时，程序可以调用GetLastError来接收错误代码。
运行效果：
代码：
using System;
using System.Collections.Generic;
using System.Text;
using System.Net.NetworkInformation; namespace ConsoleApplication1
{
class Program
{
public static void Main(string[] args)
{
string url = "www.baidu.com;www.sina.com;www.cnblogs.com;www.google.com;www.163.com;www.csdn.com";
string[] urls = url.Split(new char[] { ';' });
CheckServeStatus(urls); Console.ReadKey();
} /// <summary>
/// 检测网络连接状态
/// </summary>
/// <param name="urls"></param>
public static void CheckServeStatus(string[] urls)
{
int errCount = 0;//ping时连接失败个数 if (!LocalConnectionStatus())
{
Console.WriteLine("网络异常~无连接");
}
else if (!MyPing(urls, out errCount))
{
if ((double)errCount / urls.Length >= 0.3)
{
Console.WriteLine("网络异常~连接多次无响应");
}
else
{
Console.WriteLine("网络不稳定");
}
}
else
{
Console.WriteLine("网络正常");
}
} #region 网络检测 private const int INTERNET_CONNECTION_MODEM = 1;
private const int INTERNET_CONNECTION_LAN = 2; [System.Runtime.InteropServices.DllImport("winInet.dll")]
private static extern bool InternetGetConnectedState(ref int dwFlag, int dwReserved); /// <summary>
/// 判断本地的连接状态
/// </summary>
/// <returns></returns>
private static bool LocalConnectionStatus()
{
System.Int32 dwFlag = new Int32();
if (!InternetGetConnectedState(ref dwFlag, 0))
{
Console.WriteLine("LocalConnectionStatus--未连网!");
return false;
}
else
{
if ((dwFlag & INTERNET_CONNECTION_MODEM) != 0)
{
Console.WriteLine("LocalConnectionStatus--采用调制解调器上网。");
return true;
}
else if ((dwFlag & INTERNET_CONNECTION_LAN) != 0)
{
Console.WriteLine("LocalConnectionStatus--采用网卡上网。");
return true;
}
}
return false;
} /// <summary>
/// Ping命令检测网络是否畅通
/// </summary>
/// <param name="urls">URL数据</param>
/// <param name="errorCount">ping时连接失败个数</param>
/// <returns></returns>
public static bool MyPing(string[] urls, out int errorCount)
{
bool isconn = true;
Ping ping = new Ping();
errorCount = 0;
try
{
PingReply pr;
for (int i = 0; i < urls.Length; i++)
{
pr = ping.Send(urls[i]);
if (pr.Status != IPStatus.Success)
{
isconn = false;
errorCount++;
}
Console.WriteLine("Ping " + urls[i] + " " + pr.Status.ToString());
}
}
catch
{
isconn = false;
errorCount = urls.Length;
}
//if (errorCount > 0 && errorCount < 3)
// isconn = true;
return isconn;
} #endregion
}
}