MFC 得到本机IP和设置本机的IP

ULONG WINAPIGetAdaptersAddresses
(
  __in     ULONGFamily,
  __in     ULONGFlags,
  __in     PVOIDReserved,
  __inout  PIP_ADAPTER_ADDRESSESAdapterAddresses,
  __inout  PULONG SizePointer
);
第一个参数Family是网络协议族，用户可以指定ipv6和ipv4，这是它和GetAdapterInfo接口区别最大的地方。
第二个参数是指定地址类型的，可以指定单播、多播、ipv6、DNS等，用户可以根据需求传不同的参数得到不同的地址。
第三个是保留参数，补足位用的。
第四个参数AdapterAddresses是一个指向网卡信息结构体的指针，该指针类型是PIP_ADAPTER_ADDRESSES类型的，关于这个变量后面再详细介绍。
第五个参数是AdapterAddresses所需数据大小的值。
//网卡的信息结构体
typedef struct _IP_ADAPTER_ADDRESSES {
  union {
    ULONGLONG Alignment;
    struct {
      ULONG Length;
      DWORD IfIndex;
    };
  };
  struct _IP_ADAPTER_ADDRESSES  *Next;
  PCHAR                              AdapterName;
  PIP_ADAPTER_UNICAST_ADDRESS        FirstUnicastAddress;
  PIP_ADAPTER_ANYCAST_ADDRESS        FirstAnycastAddress;
  PIP_ADAPTER_MULTICAST_ADDRESS      FirstMulticastAddress;
  PIP_ADAPTER_DNS_SERVER_ADDRESS     FirstDnsServerAddress;
  PWCHAR                             DnsSuffix;
  PWCHAR                             Description;
  PWCHAR                             FriendlyName;
  BYTE                               PhysicalAddress[MAX_ADAPTER_ADDRESS_LENGTH];
  DWORD                              PhysicalAddressLength;
  DWORD                              Flags;
  DWORD                              Mtu;
  DWORD                              IfType;
  IF_OPER_STATUS                     OperStatus;
  DWORD                              Ipv6IfIndex;
  DWORD                              ZoneIndices[16];
  PIP_ADAPTER_PREFIX                 FirstPrefix;
  ULONG64                            TransmitLinkSpeed;
  ULONG64                            ReceiveLinkSpeed;
  PIP_ADAPTER_WINS_SERVER_ADDRESS_LH FirstWinsServerAddress;
  PIP_ADAPTER_GATEWAY_ADDRESS_LH     FirstGatewayAddress;
  ULONG                              Ipv4Metric;
  ULONG                              Ipv6Metric;
  IF_LUID                            Luid;
  SOCKET_ADDRESS                     Dhcpv4Server;
  NET_IF_COMPARTMENT_ID              CompartmentId;
  NET_IF_NETWORK_GUID                NetworkGuid;
  NET_IF_CONNECTION_TYPE             ConnectionType;
  TUNNEL_TYPE                        TunnelType;
  SOCKET_ADDRESS                     Dhcpv6Server;
  BYTE                               Dhcpv6ClientDuid[MAX_DHCPV6_DUID_LENGTH];
  ULONG                              Dhcpv6ClientDuidLength;
  ULONG                              Dhcpv6Iaid;
  PIP_ADAPTER_DNS_SUFFIX             FirstDnsSuffix;
} IP_ADAPTER_ADDRESSES, *PIP_ADAPTER_ADDRESSES;

#include 
#include 
#include 
#include 

// Link with Iphlpapi.lib
#pragma comment(lib, "IPHLPAPI.lib")

#define WORKING_BUFFER_SIZE 15000
#define MAX_TRIES 3

#define MALLOC(x) HeapAlloc(GetProcessHeap(), 0, (x))
#define FREE(x) HeapFree(GetProcessHeap(), 0, (x))

/* Note: could also use malloc() and free() */

int __cdecl main(int argc, char **argv)
{

    /* Declare and initialize variables */

    DWORD dwSize = 0;
    DWORD dwRetVal = 0;

    unsigned int i = 0;

    // Set the flags to pass to GetAdaptersAddresses
    ULONG flags = GAA_FLAG_INCLUDE_PREFIX;

    // default to unspecified address family (both)
    ULONG family = AF_UNSPEC;

    LPVOID lpMsgBuf = NULL;

    PIP_ADAPTER_ADDRESSES pAddresses = NULL;
    ULONG outBufLen = 0;
    ULONG Iterations = 0;

    PIP_ADAPTER_ADDRESSES pCurrAddresses = NULL;
    PIP_ADAPTER_UNICAST_ADDRESS pUnicast = NULL;
    PIP_ADAPTER_ANYCAST_ADDRESS pAnycast = NULL;
    PIP_ADAPTER_MULTICAST_ADDRESS pMulticast = NULL;
    IP_ADAPTER_DNS_SERVER_ADDRESS *pDnServer = NULL;
    IP_ADAPTER_PREFIX *pPrefix = NULL;

    if (argc != 2) {
        printf(" Usage: getadapteraddresses family\n");
        printf("        getadapteraddresses 4 (for IPv4)\n");
        printf("        getadapteraddresses 6 (for IPv6)\n");
        printf("        getadapteraddresses A (for both IPv4 and IPv6)\n");
        exit(1);
    }

    if (atoi(argv[1]) == 4)
        family = AF_INET;
    else if (atoi(argv[1]) == 6)
        family = AF_INET6;

    printf("Calling GetAdaptersAddresses function with family = ");
    if (family == AF_INET)
        printf("AF_INET\n");
    if (family == AF_INET6)
        printf("AF_INET6\n");
    if (family == AF_UNSPEC)
        printf("AF_UNSPEC\n\n");

    // Allocate a 15 KB buffer to start with.
    outBufLen = WORKING_BUFFER_SIZE;

    do {

        pAddresses = (IP_ADAPTER_ADDRESSES *) MALLOC(outBufLen);
        if (pAddresses == NULL) {
            printf
                ("Memory allocation failed for IP_ADAPTER_ADDRESSES struct\n");
            exit(1);
        }

        dwRetVal =
            GetAdaptersAddresses(family, flags, NULL, pAddresses, &outBufLen);

        if (dwRetVal == ERROR_BUFFER_OVERFLOW) {
            FREE(pAddresses);
            pAddresses = NULL;
        } else {
            break;
        }

        Iterations++;

    } while ((dwRetVal == ERROR_BUFFER_OVERFLOW) && (Iterations < MAX_TRIES));

    if (dwRetVal == NO_ERROR) {
        // If successful, output some information from the data we received
        pCurrAddresses = pAddresses;
        while (pCurrAddresses) {
            printf("\tLength of the IP_ADAPTER_ADDRESS struct: %ld\n",
                   pCurrAddresses->Length);
            printf("\tIfIndex (IPv4 interface): %u\n", pCurrAddresses->IfIndex);
            printf("\tAdapter name: %s\n", pCurrAddresses->AdapterName);

            pUnicast = pCurrAddresses->FirstUnicastAddress;
            if (pUnicast != NULL) {
                for (i = 0; pUnicast != NULL; i++)
                    pUnicast = pUnicast->Next;
                printf("\tNumber of Unicast Addresses: %d\n", i);
            } else
                printf("\tNo Unicast Addresses\n");

            pAnycast = pCurrAddresses->FirstAnycastAddress;
            if (pAnycast) {
                for (i = 0; pAnycast != NULL; i++)
                    pAnycast = pAnycast->Next;
                printf("\tNumber of Anycast Addresses: %d\n", i);
            } else
                printf("\tNo Anycast Addresses\n");

            pMulticast = pCurrAddresses->FirstMulticastAddress;
            if (pMulticast) {
                for (i = 0; pMulticast != NULL; i++)
                    pMulticast = pMulticast->Next;
                printf("\tNumber of Multicast Addresses: %d\n", i);
            } else
                printf("\tNo Multicast Addresses\n");

            pDnServer = pCurrAddresses->FirstDnsServerAddress;
            if (pDnServer) {
                for (i = 0; pDnServer != NULL; i++)
                    pDnServer = pDnServer->Next;
                printf("\tNumber of DNS Server Addresses: %d\n", i);
            } else
                printf("\tNo DNS Server Addresses\n");

            printf("\tDNS Suffix: %wS\n", pCurrAddresses->DnsSuffix);
            printf("\tDescription: %wS\n", pCurrAddresses->Description);
            printf("\tFriendly name: %wS\n", pCurrAddresses->FriendlyName);

            if (pCurrAddresses->PhysicalAddressLength != 0) {
                printf("\tPhysical address: ");
                for (i = 0; i < (int) pCurrAddresses->PhysicalAddressLength;
                     i++) {
                    if (i == (pCurrAddresses->PhysicalAddressLength - 1))
                        printf("%.2X\n",
                               (int) pCurrAddresses->PhysicalAddress[i]);
                    else
                        printf("%.2X-",
                               (int) pCurrAddresses->PhysicalAddress[i]);
                }
            }
            printf("\tFlags: %ld\n", pCurrAddresses->Flags);
            printf("\tMtu: %lu\n", pCurrAddresses->Mtu);
            printf("\tIfType: %ld\n", pCurrAddresses->IfType);
            printf("\tOperStatus: %ld\n", pCurrAddresses->OperStatus);
            printf("\tIpv6IfIndex (IPv6 interface): %u\n",
                   pCurrAddresses->Ipv6IfIndex);
            printf("\tZoneIndices (hex): ");
            for (i = 0; i < 16; i++)
                printf("%lx ", pCurrAddresses->ZoneIndices[i]);
            printf("\n");

            printf("\tTransmit link speed: %I64u\n", pCurrAddresses->TransmitLinkSpeed);
            printf("\tReceive link speed: %I64u\n", pCurrAddresses->ReceiveLinkSpeed);

            pPrefix = pCurrAddresses->FirstPrefix;
            if (pPrefix) {
                for (i = 0; pPrefix != NULL; i++)
                    pPrefix = pPrefix->Next;
                printf("\tNumber of IP Adapter Prefix entries: %d\n", i);
            } else
                printf("\tNumber of IP Adapter Prefix entries: 0\n");

            printf("\n");

            pCurrAddresses = pCurrAddresses->Next;
        }
    } else {
        printf("Call to GetAdaptersAddresses failed with error: %d\n",
               dwRetVal);
        if (dwRetVal == ERROR_NO_DATA)
            printf("\tNo addresses were found for the requested parameters\n");
        else {

            if (FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
                    FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, 
                    NULL, dwRetVal, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),   
                    // Default language
                    (LPTSTR) & lpMsgBuf, 0, NULL)) {
                printf("\tError: %s", lpMsgBuf);
                LocalFree(lpMsgBuf);
                if (pAddresses)
                    FREE(pAddresses);
                exit(1);
            }
        }
    }

    if (pAddresses) {
        FREE(pAddresses);
    }

    return 0;
}

https://msdn.microsoft.com/en-us/library/windows/desktop/aa365915(v=vs.85).aspx