GetIfEntry 函式 (iphlpapi.h)
GetIfEntry函式會擷取本機電腦上指定介面的資訊。
語法
IPHLPAPI_DLL_LINKAGE DWORD GetIfEntry(
[in, out] PMIB_IFROW pIfRow
);
參數
[in, out] pIfRow
在成功傳回時， MIB_IFROW 結構的指標會接收本機電腦上的介面資訊。 在輸入時，將MIB_IFROW的dwIndex成員設定為要擷取資訊的介面索引。 dwIndex的值必須由先前呼叫GetIfTable、GetIfTable2或GetIfTable2Ex 函式擷取。
傳回值
如果函式成功，傳回值會NO_ERROR。
如果函式失敗，傳回值就是下列其中一個錯誤碼。
| 傳回碼 | 描述 |
|---|---|
|
無法完成要求。 此為內部錯誤。 |
|
資料無效。 如果pIfRow參數所指向之 MIB_IFROW結構之 dwIndex成員指定的網路介面索引不是本機電腦上的有效介面索引，就會傳回此錯誤。 |
|
不正確參數已傳遞至 函式。 如果在pIfRow參數中傳遞Null指標，就會傳回此錯誤。 |
|
找不到指定的介面。 如果找不到pIfRow參數所指向之 MIB_IFROW結構之 dwIndex成員所指定的網路介面索引，就會傳回此錯誤。 |
|
不支援此要求。 如果未在本機電腦上設定 IPv4，就會傳回此錯誤。 |
|
使用 FormatMessage 取得傳回錯誤的訊息字串。 |
備註
GetIfEntry函式會擷取本機電腦上的介面資訊。
pIfRow參數所指向之MIB_IFROW結構中的dwIndex成員必須初始化為先前呼叫GetIfTable、GetIfTable2或GetIfTable2Ex函式所擷取的有效網路介面索引。
如果pIfRow參數指向之MIB_IFROW的 dwIndex成員不符合本機電腦上的現有介面索引，GetIfEntry函式將會失敗。
範例
下列範例會從介面資料表擷取專案，並列印該專案可用的一些資訊。
#include <winsock2.h>
#include <ws2tcpip.h>
#pragma comment(lib, "IPHLPAPI.lib")
#include <iphlpapi.h>
#include <stdio.h>
#include <stdlib.h>
#define MALLOC(x) HeapAlloc(GetProcessHeap(), 0, (x))
#define FREE(x) HeapFree(GetProcessHeap(), 0, (x))
/* Note: could also use malloc() and free() */
int main()
{
// Declare and initialize variables.
// Declare and initialize variables.
DWORD dwSize = 0;
DWORD dwRetVal = 0;
unsigned int i, j;
/* variables used for GetIfTable and GetIfEntry */
MIB_IFTABLE *pIfTable;
MIB_IFROW *pIfRow;
// Allocate memory for our pointers.
pIfTable = (MIB_IFTABLE *) MALLOC(sizeof (MIB_IFTABLE));
if (pIfTable == NULL) {
printf("Error allocating memory needed to call GetIfTable\n");
exit (1);
}
// Before calling GetIfEntry, we call GetIfTable to make
// sure there are entries to get and retrieve the interface index.
// Make an initial call to GetIfTable to get the
// necessary size into dwSize
dwSize = sizeof (MIB_IFTABLE);
if (GetIfTable(pIfTable, &dwSize, 0) == ERROR_INSUFFICIENT_BUFFER) {
FREE(pIfTable);
pIfTable = (MIB_IFTABLE *) MALLOC(dwSize);
if (pIfTable == NULL) {
printf("Error allocating memory\n");
exit (1);
}
}
// Make a second call to GetIfTable to get the actual
// data we want.
if ((dwRetVal = GetIfTable(pIfTable, &dwSize, 0)) == NO_ERROR) {
if (pIfTable->dwNumEntries > 0) {
pIfRow = (MIB_IFROW *) MALLOC(sizeof (MIB_IFROW));
if (pIfRow == NULL) {
printf("Error allocating memory\n");
if (pIfTable != NULL) {
FREE(pIfTable);
pIfTable = NULL;
}
exit (1);
}
printf("\tNum Entries: %ld\n\n", pIfTable->dwNumEntries);
for (i = 0; i < pIfTable->dwNumEntries; i++) {
pIfRow->dwIndex = pIfTable->table[i].dwIndex;
if ((dwRetVal = GetIfEntry(pIfRow)) == NO_ERROR) {
printf("\tIndex:\t %ld\n", pIfRow->dwIndex);
printf("\tInterfaceName[%d]:\t ", i);
if (pIfRow->wszName != NULL)
printf("%ws", pIfRow->wszName);
printf("\n");
printf("\tDescription[%d]:\t ", i);
for (j = 0; j < pIfRow->dwDescrLen; j++)
printf("%c", pIfRow->bDescr[j]);
printf("\n");
printf("\tIndex[%d]:\t\t %d\n", i, pIfRow->dwIndex);
printf("\tType[%d]:\t\t ", i);
switch (pIfRow->dwType) {
case IF_TYPE_OTHER:
printf("Other\n");
break;
case IF_TYPE_ETHERNET_CSMACD:
printf("Ethernet\n");
break;
case IF_TYPE_ISO88025_TOKENRING:
printf("Token Ring\n");
break;
case IF_TYPE_PPP:
printf("PPP\n");
break;
case IF_TYPE_SOFTWARE_LOOPBACK:
printf("Software Lookback\n");
break;
case IF_TYPE_ATM:
printf("ATM\n");
break;
case IF_TYPE_IEEE80211:
printf("IEEE 802.11 Wireless\n");
break;
case IF_TYPE_TUNNEL:
printf("Tunnel type encapsulation\n");
break;
case IF_TYPE_IEEE1394:
printf("IEEE 1394 Firewire\n");
break;
default:
printf("Unknown type %ld\n", pIfRow->dwType);
break;
}
printf("\tMtu[%d]:\t\t %ld\n", i, pIfRow->dwMtu);
printf("\tSpeed[%d]:\t\t %ld\n", i, pIfRow->dwSpeed);
printf("\tPhysical Addr:\t\t ");
if (pIfRow->dwPhysAddrLen == 0)
printf("\n");
// for (j = 0; j < (int) pIfRow->dwPhysAddrLen; j++) {
for (j = 0; j < pIfRow->dwPhysAddrLen; j++) {
if (j == (pIfRow->dwPhysAddrLen - 1))
printf("%.2X\n", (int) pIfRow->bPhysAddr[j]);
else
printf("%.2X-", (int) pIfRow->bPhysAddr[j]);
}
printf("\tAdmin Status[%d]:\t %ld\n", i,
pIfRow->dwAdminStatus);
printf("\tOper Status[%d]:\t ", i);
switch (pIfRow->dwOperStatus) {
case IF_OPER_STATUS_NON_OPERATIONAL:
printf("Non Operational\n");
break;
case IF_OPER_STATUS_UNREACHABLE:
printf("Unreasonable\n");
break;
case IF_OPER_STATUS_DISCONNECTED:
printf("Disconnected\n");
break;
case IF_OPER_STATUS_CONNECTING:
printf("Connecting\n");
break;
case IF_OPER_STATUS_CONNECTED:
printf("Connected\n");
break;
case IF_OPER_STATUS_OPERATIONAL:
printf("Operational\n");
break;
default:
printf("Unknown status %ld\n",
pIfRow->dwOperStatus);
break;
}
printf("\n");
}
else {
printf("GetIfEntry failed for index %d with error: %ld\n",
i, dwRetVal);
// Here you can use FormatMessage to find out why
// it failed.
}
}
} else {
printf("\tGetIfTable failed with error: %ld\n", dwRetVal);
}
}
exit (0);
}
需求
| 最低支援的用戶端 | Windows 2000 專業版 [僅限傳統型應用程式] |
| 最低支援的伺服器 | Windows 2000 Server [僅限傳統型應用程式] |
| 目標平台 | Windows |
| 標頭 | iphlpapi.h |
| 程式庫 | Iphlpapi.lib |
| Dll | Iphlpapi.dll |
另請參閱
SetIfEntry