asp.net获取客户端的物理地址

获取客户端的物理地址是一个比较常见的需求，可以通过以下两种方式来实现：

1. 使用ARP协议获取物理地址

在局域网中，可以通过ARP协议获取到客户端的物理地址。具体实现方式可以参考以下代码：

using System.Net;
using System.Net.NetworkInformation;

public static string GetClientMacAddress(string clientIpAddress)
{
    var macAddress = string.Empty;
    var ipAddress = IPAddress.Parse(clientIpAddress);

    var networkInterface = NetworkInterface.GetAllNetworkInterfaces()
        .FirstOrDefault(n => n.OperationalStatus == OperationalStatus.Up && n.GetIPProperties().GatewayAddresses.Any(g => g.Address.AddressFamily == ipAddress.AddressFamily));

    if (networkInterface != null)
    {
        var arp = new ARP();
        macAddress = arp.Resolve(ipAddress, networkInterface.GetIPProperties().GatewayAddresses.First().Address);
    }

    return macAddress;
}

public class ARP
{
    [DllImport("iphlpapi.dll", ExactSpelling = true)]
    public static extern int SendARP(int destIp, int srcIp, byte[] macAddress, ref uint physicalAddrLen);

    public string Resolve(IPAddress ipAddress, IPAddress gatewayAddress)
    {
        var macAddress = new byte[6];
        uint macAddrLen = (uint)macAddress.Length;

        var destIp = BitConverter.ToInt32(ipAddress.GetAddressBytes(), 0);
        var srcIp = BitConverter.ToInt32(gatewayAddress.GetAddressBytes(), 0);

        if (SendARP(destIp, srcIp, macAddress, ref macAddrLen) == 0)
        {
            var mac = BitConverter.ToString(macAddress, 0, (int)macAddrLen);
            return mac.Replace("-", ":");
        }
        else
        {
            return string.Empty;
        }
    }
}

2. 使用JavaScript获取物理地址

在Web应用程序中，可以通过JavaScript获取到客户端的物理地址。具体实现方式可以参考以下代码：

function getClientMacAddress() {
    var macAddress = "";
    var obj = new ActiveXObject("WbemScripting.SWbemLocator");
    var service = obj.ConnectServer(".");
    var properties = service.ExecQuery("SELECT * FROM Win32_NetworkAdapterConfiguration WHERE IPEnabled = 'True'");

    var e = new Enumerator(properties);
    while (!e.atEnd()) {
        var p = e.item();
        macAddress = p.MACAddress;
        break;
    }
    
    return macAddress;
}

需要注意的是，使用JavaScript获取物理地址需要在IE浏览器中运行，其他浏览器不支持ActiveXObject对象。