WinAPI技术问询：如何判断网络处于识别状态？

Great question! You're right that the INetwork COM interface is the primary way to retrieve that "Identifying Network" state, but if you want to avoid COM entirely, there are a couple of workarounds—plus, the COM approach is actually simpler than you might think. Let's cover both options:

Option 1: Simplified COM Approach (Using Network List Manager) #

Even though it's COM, you can implement this with minimal boilerplate code. The Network List Manager (NLM) exposes INetworkListManager and INetwork interfaces that directly give you the network state, including the "Identifying" status. Using ATL smart pointers handles most of the COM cleanup automatically, so you don't have to manage raw pointers manually.

Here's a practical code snippet to get you started:

#include <windows.h>
#include <netlistmgr.h>
#include <atlbase.h>
#include <vector>
#include <string>

#pragma comment(lib, "ole32.lib")

void CheckNetworkIdentifyingState() {
    HRESULT hr = CoInitializeEx(NULL, COINIT_APARTMENTTHREADED);
    if (FAILED(hr)) {
        // Handle initialization error (log or return)
        return;
    }

    CComPtr<INetworkListManager> pNLM;
    hr = pNLM.CoCreateInstance(CLSID_NetworkListManager);
    if (FAILED(hr)) {
        CoUninitialize();
        return;
    }

    CComPtr<IEnumNetworks> pEnum;
    hr = pNLM->GetNetworks(NLM_ENUM_NETWORK_ALL, &pEnum);
    if (FAILED(hr)) {
        CoUninitialize();
        return;
    }

    CComPtr<INetwork> pNetwork;
    ULONG fetched = 0;
    while (pEnum->Next(1, &pNetwork, &fetched) == S_OK && fetched > 0) {
        NLM_NETWORK_STATE state;
        hr = pNetwork->GetState(&state);
        if (SUCCEEDED(hr) && state == NLM_NETWORK_STATE_IDENTIFYING) {
            // Retrieve and display the network's friendly name
            CComBSTR bstrName;
            pNetwork->GetName(&bstrName);
            std::wstring networkName(bstrName);
            wprintf(L"Network '%s' is in **Identifying Network** state\n", networkName.c_str());
        }
        pNetwork.Release();
    }

    CoUninitialize();
}

This code enumerates all active networks, checks for the NLM_NETWORK_STATE_IDENTIFYING flag, and outputs the name of any network in that state. It's reliable because it directly queries the system's network state tracker—exactly what Windows uses to show that status in the network panel.

Option 2: Non-COM Workaround (IP Helper + DHCP Client State) #

If you absolutely want to avoid COM, you can infer the "Identifying Network" state using a heuristic approach. This checks if an interface is connected but hasn't fully resolved its network identity (e.g., empty friendly name, active DHCP lease but no stable IP yet). Note this isn't 100% accurate, but it works for most common scenarios.

Here's how to implement it with IP Helper and DHCP APIs:

#include <windows.h>
#include <iphlpapi.h>
#include <dhcpsapi.h>
#include <vector>
#include <string>

#pragma comment(lib, "iphlpapi.lib")
#pragma comment(lib, "dhcpsapi.lib")

void CheckInterfaceIdentifyingState() {
    ULONG outBufLen = 0;
    // First call to get required buffer size
    GetAdaptersAddresses(AF_UNSPEC, GAA_FLAG_INCLUDE_PREFIX, NULL, NULL, &outBufLen);
    std::vector<BYTE> buf(outBufLen);
    PIP_ADAPTER_ADDRESSES pAddresses = reinterpret_cast<PIP_ADAPTER_ADDRESSES>(buf.data());

    if (GetAdaptersAddresses(AF_UNSPEC, GAA_FLAG_INCLUDE_PREFIX, NULL, pAddresses, &outBufLen) != NO_ERROR) {
        // Handle buffer allocation/retrieval error
        return;
    }

    for (PIP_ADAPTER_ADDRESSES pCurr = pAddresses; pCurr != NULL; pCurr = pCurr->Next) {
        // Skip interfaces that aren't physically connected
        if (pCurr->OperStatus != IfOperStatusUp) continue;

        // Check DHCP client status
        DHCP_CLIENT_INFO clientInfo = {0};
        DWORD result = DhcpGetClientInfo(pCurr->AdapterName, &clientInfo);
        if (result == ERROR_SUCCESS) {
            // Heuristic: empty friendly name + active DHCP = likely identifying
            if ((pCurr->FriendlyName[0] == L'\0') || (clientInfo.ClientIpAddress.IpAddrV4 == 0)) {
                wprintf(L"Interface '%s' is likely in **Identifying Network** state\n", pCurr->Description);
            }
            DhcpFreeMemory(&clientInfo);
        }
    }
}

Recommendation #

For your ipconfig /all-style tool, the COM approach is the best choice—it's reliable, straightforward, and matches exactly what Windows uses to display the "Identifying Network" status. The ATL smart pointers take care of most of the COM complexity, so you don't have to worry about memory leaks or manual object cleanup.

内容的提问来源于stack exchange，提问作者Tony Clifton