zoukankan      html  css  js  c++  java
  • C#判断本地系统的网络连接状态

    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。
    含义
    INTERNET_CONNECTION_CONFIGURED0x40
    Local system has a valid connection to the Internet, but it might or might not be currently connected.
    INTERNET_CONNECTION_LAN 0x02
    Local system uses a local area network to connect to the Internet.
    INTERNET_CONNECTION_MODEM0x01
    Local system uses a modem to connect to the Internet.
    INTERNET_CONNECTION_MODEM_BUSY0x08
    No longer used.
    INTERNET_CONNECTION_OFFLINE 0x20
    Local system is in offline mode.
    INTERNET_CONNECTION_PROXY0x04
    Local system uses a proxy server to connect to the Internet.
    INTERNET_RAS_INSTALLED0x10
    Local system has RAS installed.
    dwReserved[in]
    保留值。必须为0。
     
    返回值:
    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。
     
    示例:
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using System.Runtime.InteropServices;
    
    namespace ConsoleApplication1
    {
        class Program
        {
            private const int INTERNET_CONNECTION_MODEM = 1;
    
            private const int INTERNET_CONNECTION_LAN = 2;
    
            private const int INTERNET_CONNECTION_PROXY = 4;
    
            private const int INTERNET_CONNECTION_MODEM_BUSY = 8;
    
            [DllImport("winInet.dll ")]
    
            //声明外部的函数:
    
            private static extern bool InternetGetConnectedState(
                ref  int Flag,
                int dwReserved
            );
    
            static void Main(string[] args)
            {
                int Flag = 0;
    
                string netStates = "";
    
                if (!InternetGetConnectedState(ref Flag, 0))
                {
                    Console.WriteLine("no!");
                }
                else
                {
    
                    if ((Flag & INTERNET_CONNECTION_MODEM) != 0)
    
                        netStates += " Connect by MODEM /n";
    
                    if ((Flag & INTERNET_CONNECTION_LAN) != 0)
    
                        netStates += "Connect by LAN  /n";
    
                    if ((Flag & INTERNET_CONNECTION_PROXY) != 0)
    
                        netStates += "Connect by PROXY /n";
    
                    if ((Flag & INTERNET_CONNECTION_MODEM_BUSY) != 0)
    
                        netStates += " MODEM is busy  /n";
    
                }
    
                Console.WriteLine(netStates);
                Console.ReadLine();
            }
        }
    }
    

    截图:

     

     

  • 相关阅读:
    图的存储代码实现
    最小生成树算法
    图的遍历
    图的存储结构
    ftp服务器的配置
    利用c++利用odbc连接mysql数据库
    测试odbc连接sqlsever数据库是否成功的代码
    gk888t打印机安装
    Win10下windows mobile设备中心连接不上的方法无法启动
    js千分位加逗号和四舍五入保留两位小数
  • 原文地址:https://www.cnblogs.com/GaoHuhu/p/3114950.html
Copyright © 2011-2022 走看看