1，获取网络的通断。

//方法1：无效果，并不能反映当前网络通断
bool available=System.Windows.Forms.SystemInformation.Network//方法2：通过VB获取网络状态，可反映当前网络通断
Microsoft.VisualBasic.Devices.Network network = new Microsoft.VisualBasic.Devices.Network();
bool available=network.IsAvailable;//方法3，可反映当前网络通断
bool available=System.Net.NetworkInformation.NetworkInterface.GetIsNetworkAvailable()

2，自定义获取Host IP ，Mac，局域网内活动IP与Mac的类。

 /// <summary>/// 本机网络连接类/// </summary>class NetworkInfo{/// <summary>/// 是否有网络连接/// </summary>public bool Available{get{return NetworkInterface.GetIsNetworkAvailable();}}/// <summary>/// 获取主机上在用的IP信息集合/// </summary>/// <returns></returns>public NetworkAddress[] GetHostNetworkAddress(){List<NetworkAddress> list = new List<NetworkAddress>();foreach (var item in NetworkInterface.GetAllNetworkInterfaces()){if (item.OperationalStatus == OperationalStatus.Up){if (item.NetworkInterfaceType == NetworkInterfaceType.Ethernet || item.NetworkInterfaceType == NetworkInterfaceType.Wireless80211){NetworkAddress info = new NetworkAddress();info.Description = item.Description;foreach (var t in item.GetIPProperties().UnicastAddresses){if (t.Address.AddressFamily == AddressFamily.InterNetwork){info.IPv4Address = t.Address.ToString();}if (t.Address.AddressFamily == AddressFamily.InterNetworkV6){info.IPv6Address = t.Address.ToString();}}string physical = item.GetPhysicalAddress().ToString();if (physical != null && physical.Length > 0){List<string> tempList = new List<string>();for (int i = 0; i < physical.Length; i += 2){tempList.Add(physical.Substring(i, 2));}physical = string.Join("-", tempList);}info.PhysicalAddress = physical;list.Add(info);}}}return list.ToArray();}/// <summary>/// 获取局域网上所有活动的IP与Mac(耗时长)/// </summary>/// <param name="ipv4">ipv4格式的IP 地址</param>/// <returns></returns>public async Task<NetworkAddress[]> ScanLocalAreaNetworkAsync(string ipv4){//格式验证if (!System.Text.RegularExpressions.Regex.IsMatch(ipv4, @"\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}")){throw new ArgumentException("格式错误，不是有效的IP地址", nameof(ipv4));}string networkNumber = ipv4.Remove(ipv4.LastIndexOf('.'));await Task.Run(() =>{// for / L % i IN(1, 1, 254) DO ping - w 2 - n 1 192.168.0.% ivar result = RunDOS($"for /L %i IN (1,1,254) DO ping -w 1 -n 1 {networkNumber}.%i");});//获取局域网中活动的IP命令：arp -astring msg = RunDOS("arp -a");//  string msg = RunDOS("ipconfig/all");var arr = System.Text.RegularExpressions.Regex.Matches(msg, @"(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})\s+(\w[0-9a-z\-]+)\s");List<NetworkAddress> list = new List<NetworkAddress>();foreach (System.Text.RegularExpressions.Match item in arr){if (item.Groups.Count == 3){NetworkAddress netip = new NetworkAddress{IPv4Address = item.Groups[1].Value,PhysicalAddress = item.Groups[2].Value};list.Add(netip);}}return list.ToArray();}/// <summary>/// 通过Ping获取活动的Local Area Network IPv4地址/// </summary>/// <param name="ipv4"></param>/// <returns></returns>public NetworkAddress[] ScanLocalAreaNetwork(string ipv4){//格式验证if (!System.Text.RegularExpressions.Regex.IsMatch(ipv4, @"\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}")){throw new ArgumentException("格式错误，不是有效的IP地址", nameof(ipv4));}string networkNumber = ipv4.Remove(ipv4.LastIndexOf('.'));List<NetworkAddress> list = new List<NetworkAddress>();Ping ping = new Ping();for (int i = 1; i < 255; i++){string targetIp = $"{networkNumber}.{i}";PingReply reply = ping.Send(targetIp, 1000);if (reply.Status == IPStatus.Success){NetworkAddress net = new NetworkAddress{IPv4Address = reply.Address.ToString(),PhysicalAddress = GetMacAddress(reply.Address.ToString())};list.Add(net);}}return list.ToArray();}/// <summary>/// 获取公网IP/// </summary>/// <returns></returns>public string GetPublicNetworkIp(){if (!Available){return "网络断开，无可用网络！";}try{WebClient client = new WebClient();string querySite = "https://qifu-api.baidubce.com/ip/local/geo/v1/district";client.Encoding = Encoding.UTF8;string result = client.DownloadString(querySite);dynamic json = Newtonsoft.Json.JsonConvert.DeserializeObject(result);string msg = $"{json.data.owner} {json.data.prov} {json.data.city} {json.ip}";return msg;}catch (Exception ex){return ex.Message;}}/// <summary>/// 运行Dos指令/// </summary>/// <param name="cmdStr">DOS命令</param>/// <returns></returns>private string RunDOS(string cmdStr){ProcessStartInfo startInfo = new ProcessStartInfo();startInfo.FileName = "cmd.exe";startInfo.UseShellExecute = false;startInfo.CreateNoWindow = true;startInfo.RedirectStandardInput = true;startInfo.RedirectStandardOutput = true;startInfo.RedirectStandardError = true;Process p = Process.Start(startInfo);//注意这里需要使用writeLine，因为这个带有回车符代表执行p.StandardInput.WriteLine(cmdStr);p.StandardInput.Close();string result = p.StandardOutput.ReadToEnd();p.WaitForExit();p.Close();return result;}public static string GetMacAddress(string RemoteIP){StringBuilder macAddress = new StringBuilder();try{Int32 remote = inet_addr(RemoteIP);Int64 macInfo = new Int64();Int32 length = 6;SendARP(remote, 0, ref macInfo, ref length);string temp = Convert.ToString(macInfo, 16).PadLeft(12, '0').ToUpper();int x = 12;for (int i = 0; i < 6; i++){if (i == 5){macAddress.Append(temp.Substring(x - 2, 2));}else{macAddress.Append(temp.Substring(x - 2, 2) + "-");}x -= 2;}return macAddress.ToString();}catch{return macAddress.ToString();}}[DllImport("Iphlpapi.dll")]static extern int SendARP(Int32 DestIP, Int32 SrcIP, ref Int64 MacAddr, ref Int32 PhyAddrLen);[DllImport("Ws2_32.dll")]static extern Int32 inet_addr(string ipaddr);///<summary>/// SendArp获取MAC地址///</summary>///<param name="RemoteIP">目标机器的IP地址如(192.168.1.1)</param>///<returns>目标机器的mac 地址</returns>}class NetworkAddress{/// <summary>/// IPv4地址/// </summary>public string IPv4Address { get; set; }/// <summary>/// IPv6地址/// </summary>public string IPv6Address { get; set; }/// <summary>/// 物理地址/// </summary>public string PhysicalAddress { get; set; }public string Description { get; set; }}

3，效果：