if (!NtQueryWnfStateData) // Handle error
The Windows Notification Facility (WNF) is a kernel-driven, publish-subscribe messaging mechanism introduced heavily in modern Windows architecture. It allows components of the operating system and high-privilege applications to exchange real-time status notifications asynchronously.
: Unlike Registry keys or global events, WNF allows you to query a snapshot of data (like battery level, network status, or system settings) atomically. ntquerywnfstatedata ntdlldll better
The NtQueryWnfStateData function is a low-level, undocumented internal export of used to query Windows Notification Facility (WNF) state information.
NtQueryWnfStateData and ntdll.dll: Mastering the Windows Notification Facility // Typically 0 PVOID StateName
The function’s job is to query the current data associated with a given WNF state name. It’s part of a family of WNF syscalls (like NtSubscribeWnfStateChange , NtUpdateWnfStateData , etc.). Because it’s undocumented and unsupported for external use, you won’t find it in the official Windows SDK.
Based on community research and reverse engineering of ntdll.dll , the function typically requires: // Input: buffer size
NTSTATUS NtQueryWnfStateData( HANDLE StateHandle, // Handle to a WNF state (if known) ULONG Unknown1, // Typically 0 PVOID StateName, // Pointer to the 128-bit WNF state name PVOID Buffer, // Output buffer for state data PULONG BufferSize, // Input: buffer size, Output: bytes written PVOID Unknown2, // Possibly timestamp or change stamp PVOID Unknown3 // Reserved );